JP2003319183A - Image processing method, image processing apparatus, and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing method, an image processing apparatus, and an image processing program for realizing output of an image of an appropriate structure, namely, an image having less noise, suppressed graininess and satisfactory sharpness irrespective of where the image data are supplied from and where the image is eventually outputted to. <P>SOLUTION: The image processing method acquires image data from an image data supply source, subjects the thus acquired image data to a first image structure processing scheme that has been set in accordance with characteristics of the image data supply source and thereafter subjects the obtained image data to a second image structure processing scheme that has been set in accordance with characteristics of an output site. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of image processing for processing image data, and more specifically, it outputs an image having an appropriate image structure regardless of an image data input source or an image data output destination. The present invention relates to an image processing method, an apparatus, and an image processing program that can be performed.

[0002]

2. Description of the Related Art Currently, when printing an image taken on a photographic film (hereinafter referred to as a film) such as a negative film or a reversal film onto a photosensitive material (photographic paper), the image of the film is projected onto the photosensitive material. The so-called direct exposure, in which exposure is performed, is the mainstream.

On the other hand, in recent years, an image photographed on a film is photoelectrically read, the obtained signal is converted into a digital signal, and various image processings are performed to obtain image data for recording. 2. Description of the Related Art Digital photo printers have been put into practical use, which expose a photosensitive material with recording light modulated according to data and output it as a print. According to such a digital photo printer, since an image is photoelectrically read and image processing is performed as digital image data,
Not only can the colors and densities of the image reproduced on the print be corrected appropriately, but it is also possible to suppress the graininess of the film and optimize the sharpness to achieve an image with a good image structure. It is possible to obtain a high quality image by performing image processing that is basically impossible with an exposure printer.

In addition to outputting an image as a print, the image data obtained by reproducing the image on the print is output as an image file to various recording media such as CD-R and MO (magneto-optical recording medium). Things are also being done. Further, not only the photographic film, but also the digital camera (the recording medium loaded therein), the recording medium such as the CD-R which has previously output the image data, and the like receive the image data, and the image carried by the image data is displayed. It is also possible to output the reproduced print.

Such a digital photo printer is basically a scanner (image reading device) for photoelectrically reading an image photographed on a film and various kinds of image processing for image data read by the scanner. An image processing device that outputs image data and a printer that receives the image data processed by the image processing device and exposes the photographic paper with recording light (for example, a laser beam) modulated according to the image data ( (Printing machine) and a printer / processor (printing machine) composed of a processor (developing machine) that develops (finishes) the photographic paper exposed by this printer and outputs it as a finished print.
Developing machine). The image processing apparatus also has a media drive and an interface for reading image data from a storage medium and outputting the image data subjected to the image processing to a recording medium (media) as an image file.

[0006]

In an ordinary digital photo printer, the image data output to the recording medium is basically the same as the image data output as a print. That is, the above-described sharpness processing is similarly performed. However, the optimum parameters for sharpness processing differ between the image reproduced on the print and the image displayed on the display. Therefore, when the image output to the recording medium is displayed on the display, there is a problem that the graininess is rough and the image is observed.

If it is a digital photo printer,
In addition to the scanner that is basically installed, for example, image data read by a scanner that reads a reflection original, a scanner of a different model, or C processed by a different system.
It is also conceivable that the image data or the like stored in a recording medium such as D-R is supplied to the image processing apparatus, processed, and output as a print or an image file. Furthermore, the image data processed by the image processing device is basically output to a printer other than the installed printer / processor, for example, an inkjet printer to create a print, or an image file in a format corresponding to a different system. It is also possible to output as.

However, the image structure of the output image differs between the scanner and the digital camera, and the image structure such as the sharpness of the output image also differs depending on the model of the scanner. Further, not only different types of output destinations such as the display and printer described above, but also different types of printers, and even different printers of the same printer / processor have different optimum parameters for sharpness processing. Therefore, the conventional digital photo printer often cannot obtain an image having an optimum image structure depending on the supply source or output destination of the image data.

An object of the present invention is to solve the above-mentioned problems of the prior art. In image processing for acquiring image data, applying image structure processing to the image data, and outputting the image data, a source of the image data is supplied. And an image processing method and apparatus capable of outputting an image having an appropriate image structure, that is, an image having good sharpness with less noise and less graininess, regardless of the output destination of image data. And to provide an image processing program.

[0010]

In order to solve the above-mentioned problems, a first aspect of the present invention is to acquire image data from an image data supply source, and use the acquired image data as a characteristic of the image data supply source. The present invention provides an image processing method characterized by performing a first image structure processing set accordingly, and then performing a second image structure processing set according to the characteristics of an output destination.

Here, it is preferable that the first image structure processing is an image structure processing for converting an image carried by the image data into an intermediate image having a predetermined image structure. Also,
It is preferable that the intermediate image is an image having an image structure corresponding to one preselected output destination. In addition, the intermediate image matches an image from which noise components or granularity depending on the image data supply source are removed, and an MTF (Modulation Transfer Function) characteristic of the image data supply source that meets a predetermined reference intermediate MTF characteristic. Or the image obtained by removing the noise component or granularity depending on the image data source and converting the MTF characteristic of the image data source to match the reference intermediate MTF characteristic. preferable.

Further, it is preferable that the first image structure processing includes processing for removing a noise component originating from the image data supply source. The image data supply source is a scanner that reads an image captured on photographic film,
The image data is image data read by the scanner from a photographed image of the photographic film, and the noise component is preferably granular. Further, it is preferable that the first image structure processing includes frequency processing for matching an MTF characteristic of the image data supply source with a predetermined reference intermediate MTF characteristic. It should be noted that in the first image structure processing, processing for removing noise components or graininess originating from the image data source is performed, and at the same time, the MTF characteristic of the image data source is set to a predetermined reference intermediate M.
It is preferable to perform frequency processing that matches the TF characteristics.

In the second image structure processing, the output MTF characteristic is calculated from the predetermined reference output MTF characteristic, the MTF characteristic of the output destination, and the observation condition, and the output MTF characteristic is calculated.
It is preferable to include frequency processing to match a predetermined reference intermediate MTF characteristic with the characteristic. Further, it is preferable that the observation conditions include an output size and an observation distance.

Further, in order to solve the above-mentioned object, a second aspect of the present invention is an image data acquisition means for acquiring image data from an image data supply source, and the image data acquired by the acquisition means is the image data. First image structure processing means for performing a first image structure processing set according to the characteristics of the data source, and the first image structure processing means for the first image structure processing means.
And an image processing device for performing second image structure processing set on the image data subjected to the image structure processing according to the characteristics of the output destination. It is a thing.

Here, it is preferable that the first image structure processing means converts an image carried by the image data into an intermediate image having a predetermined image structure. Further, it is preferable that the first image structure processing means removes a noise component or granularity derived from the image data supply source. In addition, the first image structure processing means is an MT of the image data supply source.
It is preferable to perform frequency processing so as to match the F characteristic with a predetermined reference intermediate MTF characteristic. Also, the second
The image structure processing means of the output MTF from the predetermined reference output MTF characteristic, the MTF characteristic of the output destination and the observation condition.
It is preferable to perform the frequency processing such that the characteristic is calculated and the predetermined reference intermediate MTF characteristic is matched with the output MTF characteristic.

In order to solve the above-mentioned object, a third aspect of the present invention provides an image processing program characterized by implementing the image processing method of the first aspect of the present invention. .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An image processing method, apparatus and image processing program according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram of an embodiment of a digital photo printer to which the image processing apparatus of the second aspect of the present invention for carrying out the image processing method of the first aspect of the present invention is applied. A digital photo printer (hereinafter referred to as a photo printer) 10 shown in FIG. 1 basically includes a scanner (image reading device) 12, an image processing device 14, and
It has a printer (printing / developing machine) 16 and a file output device (media drive) 17. Further, an operation system 18 having a keyboard 18a and a mouse 18b for inputting and setting various instructions, selecting and instructing image processing, inputting instructions such as color / density correction, and displaying a simulation image for verification. And a display 20 for performing operation instructions and the like by GUI.

The scanner 12 is a device for photoelectrically reading the images photographed on the film F frame by frame, that is, a film scanner, and includes a white light source 22, a variable aperture 24, a color filter plate 26, and a film. Diffusion box 2 that makes the reading light incident on F uniform in the surface direction of film F
8, an imaging lens unit 32, an area CCD sensor (hereinafter referred to as a CCD sensor) 34, an amplifier (amplifier) 36, and an A / D (analog / digital) converter 38.
Have and.

When the image captured on the film F is read by the scanner 12 as described above, the read light emitted from the light source 22 and having the light amount adjusted by the variable diaphragm 24 enters the color filter plate 26 and is adjusted. After being illuminated and diffused by the diffusion box 28, it is incident on the film F held at a predetermined reading position by the carrier and transmitted therethrough to obtain projection light carrying the image captured on the film F. This projection light is imaged on the light receiving surface of the CCD sensor 34 by the imaging lens unit 32, and the image photographed on the film F is photoelectrically read. CCD sensor 3
The output signal of No. 4 is amplified by the amplifier 36, converted into a digital signal by the A / D converter 38, and sent to the image processing apparatus 14.

The color filter plate 26 has R (red) and G (green).
And a turret with B (blue) color filters,
The color filters are rotated by known means to insert each color filter into the optical path of the reading light. In the scanner 12 of the illustrated example, the respective color filters of the color filter plate 26 are sequentially inserted and read three times to separate the image photographed on the film F into three primary colors of R, G and B. Read.

In the scanner 12, the image read on the film F is read twice, that is, a prescan for reading at a low resolution and a fine scan for obtaining image data corresponding to the output of a print or an image file. Image reading is performed. The prescan is performed under the conditions set in advance according to the prescan so that the images of all the films targeted by the scanner 12 can be read without the CCD sensor 34 being saturated. On the other hand, the fine scan is performed under the condition set for each frame according to the prescan data and the output size of the image output by the image processing device 14. Therefore, the output signals of the prescan and the fine scan are basically the same data except that the resolution and the output level of image reading are different.

In the present invention, the scanner 12 for reading an image is not limited to the example shown in the drawing, and various known scanners can be used. For example, it may be a scanner that separates an image into three primary colors and reads the images by using a light source that individually emits reading light of the three primary colors by an LED or the like. Or 3
A scanner that performs slit scanning reading using a color line CCD sensor may be used.

As described above, the output signal (image data) from the scanner 12 is output to the image processing device 14.
FIG. 2 shows a block diagram of the image processing device 14. The image processing device (hereinafter, referred to as a processing device) 14 includes a data correction unit 46, a Log converter 48, a prescan frame memory (hereinafter, PSFM) 50, a fine scan frame memory (hereinafter, FSFM) 52. , A setup unit 54, a verification processing unit 56, an output processing unit 58, and an input processing unit 60. Although FIG. 2 mainly shows parts related to image processing, the processing device 14 also controls and manages the entire photo printer 10 such as the operation of each part according to the input output method. In addition to the parts shown in FIG. 2, a CPU for controlling the whole, a memory for storing information necessary for the operation of the photo printer 10 and the like are arranged. Further, although not shown, the image processing device 14
Has a media drive and an interface for acquiring image data from various input devices described later. The media drive functioning as the file output device 17 may be used as an input device for reading and inputting image data from various recording media.

The data correction section 46 is a section for performing predetermined processing such as DC offset correction, dark correction, shading correction, etc. on each of the R, G and B output data output from the scanner 12. The Log converter 48 Log-converts the output data processed by the data correction unit 46 using, for example, an LUT (look-up table) or the like to obtain digital image (density) data. The prescan (image) data converted by the Log converter 48 is PSFM50.
The fine scan (image) data is FSFM52.
Are stored in each.

The photo printer 10 includes, in addition to the standard scanner 12, a film scanner of another model, a scanner of a reflection original, a digital camera, and a CD-R output by the photo printer 10 (described later). Standard CD
-R) or other recording medium or a media drive such as a storage medium storing image data output from another system (including a digital camera) (hereinafter, including the scanner 12, these are collectively referred to as an input device) It is a system that can acquire image data, process the image data, and output it. In the present invention, the input device, ie, the scanner 12 and other input devices, are the image data source. The image data acquired from such an input device is sent to the input processing unit 60. The input processing unit 60 performs necessary processing such as decompression, color space conversion, electronic scaling (enlargement / reduction processing) on these image data, and the image data (pre-scan data and fine scan) corresponding to the image processing unit 14 is processed. Data) and convert to PSFM
50 and FSFM52.

The setup unit 54 uses the prescan data stored in the PSFM 50 to determine the fine scan reading conditions and the image processing conditions in the verification processing unit 56 and the output processing unit 58 (image processing unit 62). Further, when the color / density of the image is corrected by the verification, the image processing condition corresponding to this correction is determined, or the image processing condition previously determined is corrected. The image processing conditions in the setup unit 54 may be determined by a known method using image analysis or the like according to the image processing to be performed. The image processing conditions uniquely determined according to the input image size, the output image size, etc. may be stored in a table in advance.

The verification processing unit 56 performs image processing on the prescan data according to the image processing conditions determined by the setup unit 54, and further converts the prescan data into image data corresponding to the image display on the display 20, and a predicted finished image ( It is a part displayed on the display 20 as a verification image). The display 20 is not particularly limited, and C
RT (Cathode Ray Tube) display, liquid crystal display (LCD) and plasma display panel (PDP)
Various known display means such as the above can be used.

The output processor 58 has an image processor 62, a sharpness processor 64, a data converter 66, a file processor 68, and a device processor 70.

The image processing section 62 is a section for performing various kinds of image processing on the fine scan data according to the image processing conditions determined by the setup section 54. Image processing unit 62
There is no particular limitation on the image processing to be performed in, for example, color / density correction, gradation conversion, color balance correction, saturation correction, dodging processing (adding dodging effect in direct exposure printing by image data processing), etc. Is exemplified. These image processes may be performed by a known method using a look-up table (LUT), matrix (MTX) operation, low-pass filter (LPF), or the like.

The sharpness processing section 64 is one of the parts for carrying out the image processing method of the present invention, and is a part for performing the image structure processing according to the input and the image structure processing according to the output, which is the feature of the present invention. is there. In the following, as image structure processing,
Although sharpness processing will be described as a typical example, the present invention is not limited to this. Examples of the image structure processing applied to the present invention include sharpness processing, noise removal processing, frequency processing, and the like.

Here, as the image structure processing according to the input performed in the sharpness processing unit 64, for example, a noise component derived from an input destination, that is, an image data supply source,
In the case of an image scanned with a scanner from a film image, grain removal processing and MTF (Modulation Transf
er function) characteristic to match a predetermined reference intermediate MTF characteristic. It is preferable that these noise component or granular removal processing and frequency processing are performed at the same time. As the image structure processing according to the output performed by the sharpness processing unit 64, for example, the output MTF characteristic is calculated from a predetermined reference output MTF characteristic, output device MTF characteristic, and observation condition (output size and observation distance). , Frequency processing for matching the reference intermediate MTF characteristic with the output MTF characteristic. Further, the intermediate image having a predetermined image structure obtained by the image structure processing according to the input is an image from which the noise component (granularity) depending on the input destination is removed, and the reference intermediate point in which the MTF characteristic of the input destination is predetermined An image converted so as to match the MTF characteristic, or an image that has been subjected to the above-described removal processing and frequency processing at the same time.

In the illustrated example, the sharpness processing unit 64
Has a first sharpness processing means 64a and a second sharpness processing means 64b (see FIG. 3), and the first sharpness processing means 64a performs sharpness processing (that is, image structure) according to a source of image data such as the scanner 12. Processing) to convert the image into an intermediate image having a predetermined image structure, and then the second sharpness processing means 64b processes the intermediate image for sharpness processing (that is, image structure) according to the output destination of the printer 16 or the like. Process) and output to the next step. The detailed configuration and function of the sharpness processing unit 64 will be described later. Although the sharpness processing unit 64 is arranged downstream of the image processing unit 62 in the illustrated example, the present invention is not limited to this, and may be arranged upstream of the image processing unit 62, or The sharpness processing unit 64 may be arranged in the image processing unit 62, and the sharpness processing may be performed during the image processing performed by the image processing unit 62.

The data conversion unit 66 converts the image data into image data corresponding to the image recording by the printer 16 using, for example, a 3D (three-dimensional) -LUT, and the printer 1
It is a part to output to 6. Note that the printer 16 exposes a photographic printing paper (photosensitive material) according to the image data output from the data conversion unit 66 to record a latent image, develops it, and outputs it as a (finished) print. A printer / processor (printing / developing machine). For example, the printer 16 cuts the photographic paper according to the print size, performs back printing, etc., and then outputs the light beam to image data (recorded image).
According to the two-dimensional scanning by modulating and deflecting in the main scanning direction, and by conveying the photographic paper in the sub-scanning direction orthogonal to the main scanning direction, a latent image is recorded on the photographic paper, The photographic printing paper on which the latent image is recorded is subjected to predetermined wet development processing such as color development, bleach-fixing, washing with water, dried to form a print, and then sorted and accumulated.

Further, the photo printer 10 in the illustrated example can output not only printing but also image data as an image file. As an example, the photo printer 10 outputs the image data processed by the image processing device 14 as JPEG (Joint Phot) as a standard output of the image file.
It is recorded on a CD-R (standard CD-R as described above) as an image file in the ographic Expert Group format and is output as a recorded CD-R (standard CD-R). The file processing unit 68 is a part that performs this image file conversion processing, converts the image data into image data according to JPEG image file output using a 3D-LUT or the like, and then,
This image data is converted into a JPEG image file, recorded on the CD-R by the file output device 17, and output from the file output device 17 as a standard CD-R. The image file may be tagged with a standard CD-R image file from the printer 10. The standard image file format is JPEG.
However, various formats such as Exif and JPEG2000 are all available.

The photo printer 10 in the illustrated example is not limited to the print output by the standard printer 16 and the standard CD-R output by the file output device 17, but may be another type of printer / processor, ink jet printer, or the like. Different types of printers such as electrophotographic printers, CDs
-R is a CD-R output (non-standard) as an image format different from JPEG such as bitmap or GIF, and a media drive for recording on a recording medium other than CD-R (hereinafter, these are collectively referred to as an output device. Image data can also be output. In the present invention, the printer 16, the file output device 17, and the output device are output destinations of the processed image data. The printer 16 and the file output device 17 may be included in the output device. The device processing unit 70 is instructed by performing conversion of image data such as color space, compression processing, image formatting, addition of a tag indicating that the photo printer 10 has output, etc. according to the output device that is the output destination. Output to the output device.

In the photo printer 10 of the illustrated example, the output of the image data is not limited to one output destination. For example, the output of the multiple sharpness processing section 64 such as the simultaneous output of print and standard CD-R. The image data may be output at the same time first.

As described above, in the photo printer 10,
Image data is supplied from various input devices other than the scanner 12, and the printer 16 and the standard CD-R are also supplied.
Image data is also supplied to various output devices other than the above. The sharpness processing unit 64 of the image processing device 14 performs sharpness processing (image structure processing) on the supplied image data according to the types of the scanner 12 and other input devices.
Is performed to form an intermediate image having a predetermined image structure, and the intermediate image is subjected to sharpness processing according to the types of the printer 16 (print), the file output device 17 (standard CD-R) and the output device. FIG. 3 shows the configuration of the sharpness processing unit 64 and the sharpness processing unit 6 as described above.
The processing in 4 is conceptually shown.

As an example, the photo printer 10 of the illustrated example includes three types of film scanners (scanner A, scanner B, and scanner C) different from each other in addition to the scanner 12, a standard CD-R, and a digital camera. Image data can be acquired by a media drive from a recording medium (medium A) that stores captured image data and a storage medium (media B) that stores image data processed by a computer or the like. Further, as one embodiment, the print output by the printer 16 and the standard CD-
In addition to R output, image data is output by a media drive to three different types of printers (printer A, printer B, and printer C) and recording media intended to be used by a computer. Note that, for example, the printer A is a printer / processor of a different model from the printer 16, the printer B is an inkjet printer, and the printer C is an inkjet printer of a different model from the printer B.

The sharpness processing unit 64 includes a scanner 1
2 and media A (drive), etc., the sharpness processing conditions for obtaining an intermediate image having a predetermined image structure are set corresponding to the characteristics of the image data supply source (input destination). . Further, the sharpness processing unit 64 corresponds to the characteristics of the output destination of the printer 16, the printer A, or the like, and correspondingly corresponds to the intermediate image, the image of the optimum image structure, that is, the noise is small, for example, the film image. In, the sharpness processing condition is set so that graininess is suppressed and an image having an appropriate sharpness is obtained. That is, in the sharpness processing unit 64, the first sharpness processing means 64a performs sharpness processing depending on each input destination on the image data acquired from the input destination to form an intermediate image, and the second sharpness processing means is applied to this intermediate image. By performing sharpness processing depending on the output destination by 64b, an output image having an optimum image structure for each output destination is obtained.

Incidentally, the predetermined image structure in the intermediate image may be appropriately set to an image structure which can commonly correspond to all the input destinations in accordance with the assumed input destinations. Alternatively, the photo printer 10 may select one corresponding output destination and the optimum image structure for this output destination may be the image structure of the intermediate image. In the illustrated example, as an example, the target image structure in the standard CD-R is the image structure of the intermediate image. Therefore, the image data acquired from any of the input destinations has the standard CD-R image structure in the intermediate image. The image data of the standard CD-R is, for example, for the purpose of mainly observing an image on a monitor such as a personal computer,
The corresponding optimum image structure is the standard CD-R, that is, the image structure of the intermediate image.

FIG. 4 shows a block diagram of an embodiment of the sharpness processing means 64a and 64b in the sharpness processing section 64. The sharpness processing means 64
Since a and 64b have the same configuration, the sharpness processing means 64a will be described as a representative example. As shown in the figure, the sharpness processing means 64
a and 64b are the first LPF 80, the first subtractor 82,
Luminance component extraction unit 84, second LPF 86, second subtractor 8
8, first amplifier 90, second amplifier 92, first adder 94
And a second adder 96.

In the sharpness processing means 64a of the illustrated example, first, the image data supplied from the image processing section 62 (hereinafter referred to as original signal S _F (R, G, B))
The low frequency components R _L , G _L , and B _L of the original signal S _F (R, G, B) are extracted by processing with the LPF 80, and the first subtractor 82
And to the second adder 96. The first LPF 80 is, for example, a 9 × 9 LPF. The first subtractor 82 converts the low frequency components R _L , G _L , and B _L from the original signal S _F (R, G, B).
Is subtracted to extract the intermediate and high frequency components R _MH , G _MH , and B _MH . That is, in the illustrated example, the image data is
It is decomposed into two frequency components, a low frequency component and an intermediate / high frequency component.

Next, the luminance component extraction unit 84 extracts the components on the higher frequency side, that is, the intermediate / high frequency components R _MH , G _MH , and B _MH obtained by the first subtractor 82 from the luminance component Y _MH. To extract. The luminance component Y _MH is
The high-frequency components R _MH , G _MH , and B _MH are luminance components converted according to the YIQ standard, and the luminance component extraction unit 84 extracts (calculates) the luminance component Y _MH by MTX calculation, for example.
To do.

Next, the luminance component Y _MH extracted by the luminance component extracting section 84 is subjected to a filtering process by the second LPF 86 to obtain an intermediate frequency component Y of the luminance component Y _{MH.
Get M.} The second LPF 86 is, for example, a 5 × 5 LPF.
Is. In the second subtractor 88, the luminance component Y _MH
By subtracting the intermediate frequency component Y _M from, the high frequency component Y _H of the luminance component Y _MH is obtained.

Further, in the first amplifier 90, the second L
Gain M (ga the intermediate frequency components Y _M obtained in PF86
The INM), while in the second amplifier 92, the high frequency components Y _H obtained by subtracting the gain H (GainH),
Each multiplied to obtain the processed components Y _'M, Y' and _H. The gain (sharpness gain) is usually the gain M is relatively low with respect to the intermediate frequency components Y _M, the gain H for the high-frequency component Y _H is set to a relatively increased. This makes it possible to obtain an image in which noise (granularity) in the image is suppressed and the sharpness is suitably emphasized. However, in the present invention, that is, the sharpness processing means 64 in the illustrated example.
In a, the gains M and H are set according to the input destination of the image data to be sharpened in order to perform the input destination-dependent sharpness processing which is a feature of the present invention.

[0047] Then, the processed components Y _'M and Y' _H obtained by the first amplifier 90 and second amplifier 92, first
The component _Y'MH is obtained by combining in the adder 94. Further, in the second adder 96, the component Y ′ _MH thus obtained is converted into the low frequency component R _L of the original signal S _F ,
By combining with G _L and B _L , image data R ′, G ′, and B ′ whose sharpness is emphasized according to the input destination are obtained. The image data R ', G', B'obtained in this way become image data of an intermediate image subjected to the input destination-dependent sharpness processing. Next, the image data R ′, G ′, B ′ of the intermediate image thus obtained is processed by the sharpness processing means 6 of the illustrated example.
In 4b, it is first supplied as the original signal S _F (R, G, B). Hereinafter, the sharpness processing means 6 in the illustrated example
4b, in the same manner as in the case of the sharpness processing means 64a, except that the gain M and H set according to the output destination of the image data to be sharpened is used, and the output destination-dependent sharpness processing which is a feature of the present invention. The image data R ′, G ′, B ′ whose sharpness is emphasized according to the output destination can be obtained. The image data R ′, G ′, B ′ thus obtained are supplied to one or more of the data conversion unit 66, the file processing unit 68, and the device processing unit 70, as described above.

Photo printer 10 (image processing device 14)
In the above, the gain M and the gain H corresponding to the respective characteristics are set as the processing conditions of the input destination-dependent sharpness processing and the output destination-dependent sharpness processing in correspondence with the respective input destinations and output destinations.

As described above, in the illustrated example, the standard C
The image structure of D-R is the image structure of the intermediate image,
The input-destination-dependent sharpness processing is processing for converting an image into an intermediate image of this image structure. Corresponding to this, for example,
When the image read by the scanner 12 has a large noise (graininess is rough) and a sharpness is low as compared with the image of the standard CD-R, the gain M is smaller than that of the process of the standard CD-R. The processing condition that is low and the gain H is high is set as the processing condition of the input destination-dependent sharpness processing corresponding to the scanner 12. In addition, the image of the medium A (digital camera) has less noise than the image of the standard CD-R,
When the sharpness is low, compared to the standard CD-R treatment,
Higher processing conditions for both the gain M and the gain H are set as the processing conditions for the input destination-dependent sharpness processing corresponding to the medium A. Further, when the scanner A is a device that performs sharpness processing inside the device and the image has a large amount of noise and a high sharpness, both the gain M and the gain H are lower than those of the standard CD-R processing. Is set as the processing condition of the input destination-dependent sharpness processing corresponding to the scanner A. That is, the standard CD-R is used as the processing condition of the input destination-dependent sharpness processing.
With respect to the image (intermediate image), processing conditions that cancel the characteristics of the input destination are set corresponding to each input destination.

On the other hand, as a processing condition of the output destination-dependent sharpness processing, an image obtained by processing a standard CD-R image (intermediate image) has an optimum image structure corresponding to each output destination. Such conditions are set corresponding to each output destination. For example, in the printer 16, when an image having higher sharpness and low noise (graininess is suppressed) is preferable, a processing condition in which the gain M is low and the gain H is high is output corresponding to the printer 16. It is set as the processing condition of the destination-dependent sharpness processing. Also, printer B
In an (inkjet printer), when an image with significantly suppressed noise is preferable, a processing condition with a low gain M is set as a processing condition of output destination-dependent sharpness processing corresponding to the printer B. Similar to the input destination-dependent processing condition, when the output destination is the standard CD-R, the processing condition of unprocessed is set as the processing condition of the output destination-dependent sharpness processing. As described above, when the input destination or the output destination is the standard CD-R, the processing condition of unprocessed may be set as the processing condition of the input destination or the output destination dependent sharpness processing, but the sharpness processing means 64a. Alternatively, 64b may be passed through.

In the sharpness processing unit 64, when the image data is received from the image processing unit 62, first, the sharpness processing means 64a shown in FIG. Generate an image. The determination of the input destination in the sharpness processing unit 64 may be performed by a known method such as attaching a tag indicating the input destination to the image data. In the sharpness processing unit 64, the sharpness processing unit 64b shown in FIG. 4 then performs output destination-dependent sharpness processing on the generated intermediate image with a gain corresponding to the designated output destination, and outputs the image data to the output destination. Corresponding to, the data conversion unit 66 for the printer 16, the file processing unit 68 for the standard CD-R, the device processing unit 70 for other output devices, the image data subjected to the sharpness processing, Output. Therefore, according to the present invention,
It is possible to output a high-quality image having an appropriate image structure to any of the output destinations regardless of the input destination (image data supply source).

In the above example, the gain of the sharpness processing is changed according to the characteristics of the input / output destinations, but the present invention is not limited to this, and L is adjusted according to the characteristics of the input / output destinations.
The frequency characteristics of the PF may be changed, and the gain and L
Both of the changes in the frequency characteristics of the PF may be used together. Further, the sharpness processing method (sharpness processing algorithm) is not limited to the above-mentioned method, and various methods can be used. For example, it is possible to use a sharpness processing method in which averaging is performed using a so-called unsharpness mask, a difference from the average is obtained, the difference is multiplied by a coefficient, and the obtained numerical value is added to image data. In addition, it enables multiple sharpening methods to be executed,
The sharpness processing method may be changed according to the characteristics of the input / output destination.

The image structure of the intermediate image may not necessarily properly correspond to all input destinations. At this time, the image structure of the intermediate image may not be appropriate depending on the input destination, and as a result, the image structure of the output image may be incorrect. Correspondingly, for example, when the image data acquired from the scanner A is output to the printer 16, output destination-dependent sharpness processing is performed under a predetermined condition according to the printer 16, and the image data acquired from the scanner B is transferred to the printer 16. When outputting to, the output destination-dependent sharpness processing condition, such as performing output destination-dependent sharpness processing under a condition different from the predetermined condition according to the printer 16,
You may change according to the kind of input destination. The determination of the input destination at this time may be performed by a method such as attaching a tag indicating the input destination to the intermediate image. In order to handle such processing, when outputting image data to a medium, a tag indicating that the image data is image data created by the photo printer 10 may be added to the image file.

The image processing method according to the first aspect of the present invention and the image processing apparatus according to the second aspect of the present invention are basically configured as described above, but the present invention is not limited to this. As in the third aspect of the present invention, the above-described image processing method of the first aspect of the present invention may be realized as an image processing program that operates on a computer.

Although the image processing method, apparatus, and image processing program of the present invention have been described above in detail with reference to various embodiments and examples, the present invention is not limited to these embodiments and examples. It goes without saying that various improvements and changes may be made without departing from the scope of the present invention.

[0056]

As described above in detail, according to the present invention, in the image processing for acquiring the image data, performing the image structure processing and outputting the image data, the source of the image data and the output destination of the image data. Regardless of this, it is possible to output an image having a proper image structure with less noise and good sharpness.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a digital photo printer that implements an image processing method of the present invention.

FIG. 2 is a block diagram of an embodiment of an image processing apparatus of the digital photo printer shown in FIG.

FIG. 3 is a diagram conceptually showing sharpness processing performed by the image processing method of the present invention.

FIG. 4 is a block diagram of an embodiment of a sharpness processing unit in the image processing apparatus shown in FIG.

[Explanation of symbols]

10 (Digital) Photo Printer 12 scanner 14 (Image) processing device 16 Printer 18 Operation system 20 display 22 Light source 24 variable aperture 26 color filter plate 28 diffusion box 32 Imaging lens unit 34 (area) CCD sensor 36 amplifier 38 A / D converter 46 Data correction unit 48 Log Converter 50 prescan (frame) memory 52 Fine scan (frame) memory 54 Setup Department 56 Verification processing section 58 Output processing unit 62 Image processing unit 64 Sharpness processing section 64a, 64b Sharpness processing means 66 Data converter 68 Face Processing Unit 70 Device processing unit 80 1st LPF (low pass filter) 82 first subtractor 84 Luminance component extraction unit 86 Second LPF 88 Second Subtractor 90 First amplifier 92 Second amplifier 94 First adder 96 Second adder

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/91 H04N 1/40 101C 5/91 HF term (reference) 2C187 AC07 AC08 AD13 AF03 BF08 CC08 5B021 AA01 CC05 DD11 LG07 LG08 5B057 AA11 BA02 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC01 CE02 CE03 5C053 FA04 FA07 KA01 KA24 LA03 LA11 5C077 LL02 LL19 MP01 MP08 NN02 PP03 PQ08 SS02 TT02

Claims (15)

[Claims] 1. Image data is acquired from an image data source, the acquired image data is subjected to a first image structure processing set according to the characteristics of the image data source, and thereafter,
An image processing method comprising performing a second image structure process set according to the characteristics of an output destination. 2. The image processing method according to claim 1, wherein the first image structure processing is an image structure processing for converting an image carried by the image data into an intermediate image having a predetermined image structure. 3. The image processing method according to claim 2, wherein the intermediate image is an image having an image structure corresponding to one preselected output destination. 4. The intermediate image is an image from which noise components or granularity depending on the image data source is removed, and MTF (Modulation Transfer Functio) of the image data source.
n) An image whose characteristics have been converted to match a predetermined reference intermediate MTF characteristic, or the noise component or granularity depending on the image data source is removed, and the MTF characteristic of the image data source is set to the reference. The image processing method according to claim 2, wherein the image is an image converted to match the intermediate MTF characteristic. 5. The image processing method according to claim 1, wherein the first image structure processing includes processing for removing a noise component originating from the image data supply source. 6. The image data supply source is a scanner for reading an image photographed on photographic film, the image data is image data read by the scanner from a photographed image of the photographic film, and the noise The image processing method according to claim 5, wherein the component is granular. 7. The image processing according to claim 1, wherein the first image structure processing includes frequency processing for matching an MTF characteristic of the image data source with a predetermined reference intermediate MTF characteristic. Image processing method. 8. In the second image structure processing, an output MTF characteristic is calculated from a predetermined reference output MTF characteristic, the MTF characteristic of the output destination, and an observation condition, and a predetermined reference is set for the output MTF characteristic. The image processing method according to any one of claims 1 to 7, further comprising frequency processing for matching the intermediate MTF characteristics. 9. The image processing method according to claim 8, wherein the observation conditions include an output size and an observation distance. 10. An image data acquisition means for acquiring image data from an image data supply source, and a first image structure processing set in the image data acquired by the acquisition means according to the characteristics of the image data supply source. And a second image structure processing unit that sets the image data that has been subjected to the first image structure processing by the first image structure processing unit according to the characteristics of the output destination. An image processing apparatus, comprising: a second image structure processing means for performing 11. The image processing apparatus according to claim 10, wherein the first image structure processing means converts an image carried by the image data into an intermediate image having a predetermined image structure. 12. The image processing apparatus according to claim 10, wherein the first image structure processing means removes noise components or graininess derived from the image data supply source. 13. The first image structure processing means determines a MTF characteristic of the image data source by a predetermined reference intermediate M.
11. The frequency processing is performed so as to match the TF characteristic.
The image processing device according to any one of 1 to 12. 14. The second image structure processing means calculates an output MTF characteristic from a predetermined reference output MTF characteristic, the MTF characteristic of the output destination, and an observation condition, and the output MTF is calculated.
The image processing device according to claim 10, wherein frequency processing is performed so as to match a predetermined reference intermediate MTF characteristic with the characteristic. 15. An image processing program for carrying out the image processing method according to any one of claims 1 to 9.