JPH0564006A - Picture data supply controlling system - Google Patents

Abstract

PURPOSE:To prevent the futile transmission of data by providing a code data storage part, a picture restoring part, and a code data supply control part. CONSTITUTION:The code data storage part 11 in which the code data of plural pictures having hierarchical structure is stored, the picture restoring part 13 to restore an original picture from the code data, and the code data supply control part 12 to control the number of the hierarchies of the code data to be supplied from the code data storage part 11 in accordance with the resolution of the picture restoring part 13 are provided. Thus, the number of the hierarchies of the code data corresponding to the resolution of the output display device of a restoring side is determined, and the supply of the code data is controlled so that only the code data up to the number of the hierarchies required for satisfying the resolution is supplied. Thus, the picture can be restored efficiently by supplying the code data to meet the resolution required for the output display of the picture, and the transmission of the code data to the restoring side in the retrieval of a picture data base can be executed efficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image data supply control system for hierarchically restoring an image from code data obtained by encoding a multivalued image in block units. In order to store image data whose information amount is orders of magnitude larger than numerical data, especially halftone image and color image data, or to transmit at high speed and high quality, the gradation value for each pixel is highly efficient. Need to be encoded into.

[0002] At present, as a method of encoding image data in an image database search or the like, it is possible to gradually improve the image quality from a coarse image to a high quality image and restore it.
For example, a hierarchical coding method using an adaptive discrete cosine transform coding method (ADCT) is being studied. Furthermore, the development of an image data supply control method in a transmission device and a restoration device for realizing efficient transmission and restoration of hierarchically encoded image data, and for achieving an efficient image database search, etc. Strongly desired.

[0003]

2. Description of the Related Art A conventional hierarchically encoded image data supply control system will be described with reference to the flowchart of FIG. Now, as shown in FIG. 10, three images 1, 2, 3
It is assumed that the code data of is present. Each image A, B, C
Code data of 1-1 to 1-5, 2-1 to 2-
It is composed of five layers of 5, 3-1 to 3-5.

To restore an image from coded data having such a hierarchical structure, if the image A is first selected as the first image in step S1, the next step S2 is from the first layer to the last layer of the image A. Code data 1-1 to 1-5
To supply sequentially. When the supply of code data of all layers is completed, it is checked in step S3 whether or not the next image exists, and if there is, the process proceeds to step S5 to select the next image B,
2, the code data 2-1 to 2- of all layers of the next image B are returned.
Supply 5. Similarly, the same supply process of the code data 3-1 to 3-5 is repeated for the image C, and if there is no next image, the supply of the image is ended.

[0005]

However, in such a conventional image data supply control system, since the code data of all layers of each image is supplied, the image data restoration device and the image data transmission device are Until the supply of code data for all layers is completed, the next image cannot be restored or transmitted, making it difficult to efficiently search the image database.

Further, in the image data transmission apparatus using the conventional image data supply control method, the coded data of all the layers is always output to the restoration side regardless of the display capability of the display device for outputting the restored image, that is, the resolution. It is supplied to the device, and for example, to an output device having a low resolution, an image quality higher than the display capability is sent, and there is a problem in that code data is wasted.

The present invention has been made in view of the above-mentioned conventional problems, and supplies code data for layers corresponding to the resolution of the display device on the restoration side to prevent waste of data transmission. It is an object of the present invention to provide a controlled image data supply control method.

[0008]

FIG. 1 is a principle explanatory view showing an image data supply control system of the present invention. First, the present invention is directed to an image data supply control method for supplying coded data obtained by coding an original image by dividing it into two or more layers. In the present invention as such an image data supply control system, a code data storage unit 11 that stores code data of a plurality of images having a hierarchical structure, an image restoration unit 13 that restores an original image from the code data, and an image A code data supply control unit 12 that controls the number of layers of code data supplied from the code data storage unit 11 according to the resolution of the restoration unit 13 is provided.

Here, the code data supplied by the code data supply control unit 12 is sent to the image restoration unit 1 via the communication line.
3 may be used for data transmission. Further, the code data supply control unit 12 has a display condition designating unit 21 that designates how many layers the image data of one image is to be restored according to the type of resolution at the time of image restoration, and the number of designated layers of the display condition designating unit 21. From among the above, the control unit 22 that controls the supply of the code data by selecting the number of layers corresponding to the resolution of the image restoration unit 13, and the corresponding code data from the code data storage unit 11 under the control of the control unit 22 is used as a layer unit. And a code selection unit 23 which sequentially supplies the image to the image restoration unit 13.

Further, the code data storage unit 11 shows how many layers are restored according to the type of resolution at the time of image restoration in order to enable the supply control of the code data according to the present invention corresponding to the resolution on the restoration side. The number of layers data is stored in advance for each code data of each image. For such a code data storage unit 11, a code data supply control unit 12
Is the image restoration unit 1 from the layer number data added to the coded data of the restored image stored in the coded data storage unit 11.
The number of layers for obtaining the resolution of 3 is detected, and the code data is supplied to the image restoration unit 13 in units of layers until the number of layers is obtained.

Further, in the code data storage unit 11, the original image is divided into blocks each consisting of a plurality of pixels, and the gradation values of the plurality of pixels in this block are two-dimensionally discrete cosine transformed (DCT). Quantize the obtained DCT coefficient,
Further, the quantized coefficient obtained by quantizing the DCT coefficient is encoded and the code data of one image divided into a plurality of layers is stored.

Further, the image restoration unit 13 decodes the quantized coefficient from the coded data in units of layers and then inversely quantizes the DCT.
Coefficients are converted into two-dimensional discrete cosine transform (inverse DC)
Perform T) to restore the original image data.

[0013]

According to the image data supply control system of the present invention having such a configuration, the following actions shown in the flowchart of FIG. 2 can be obtained. First, as shown in step S1, the display condition indicating the resolution of the image restoration unit 13 is received and set in the control unit 22 of the code data supply control unit 12. The setting of the display condition indicating the resolution on the restoration side with respect to the control unit 22 may be performed by an operator's input operation or by data transmission with the image restoration unit 13.

Next, as shown in step S1, the code selection unit 23 instructs the code data storage unit 1 in accordance with an instruction from the control unit 22.
The first image stored in 1 is selected, and then step S3
Then, the number of layers of code data satisfying the resolution on the restoration side is calculated. In order to calculate the number of layers corresponding to this resolution, for example, data indicating the number of layers corresponding to the type of resolution on the restoration side is added in advance to the beginning of the code data in the code data storage unit 11. Therefore, the display condition specifying unit 21 stores the layer number data indicating the number of supply layers according to the type of resolution added to the beginning from the code data of the first image input to the code selecting unit 23.

Subsequently, the control unit 22 controls the display condition designating unit 21.
The display condition of the image restoration unit 13, that is, the number of layers corresponding to the resolution is detected from the number of layers to be supplied corresponding to the type of resolution stored therein, and the supply condition of code data is determined. When the supply condition of the code data is determined in step S3, the control unit 22 sequentially controls the code data of the first image in hierarchical units until the determined number of layers is reached by the control of the code selecting unit 23, as shown in step S4. It is supplied to the image restoration unit 23.

When the code data for the designated layer is supplied in step S4, the process proceeds to step S5, the presence or absence of the next image is checked, and if the next image exists, the control unit 22 proceeds to step S5.
In step 6, the code selection unit 23 is instructed to finish the supply of the hierarchical code data of the first image and select the second image data. Also for the second image, the supply of the layer code data based on the determination of the number of layers according to the resolution is continued in steps S3 to S6.

If there is no next image in step S5 (end of supply of all images), the control unit 22 determines the end of supply.

[0018]

FIG. 3 is a block diagram of an embodiment showing one embodiment of the present invention. In FIG. 3, 11 is a code data storage unit, 1
Reference numeral 2 is a code data supply control unit, and 13 is an image restoration unit.
In the present embodiment, the code data storage unit 11 stores three pieces of image data A, B, C, and each of the image data A, B, C has five layers of code data 1-1 to 1-. 5,2
-1 to 2-5 and 3-1 to 3-5. As the code data storage unit 11, a suitable storage device such as a semiconductor storage device, a magnetic storage device, or an optical recording device can be used.

Further, the coded data storage unit 11 stores coded data obtained by DCT conversion. In the code data by the DCT conversion, the original image is divided into blocks each having a plurality of pixels, for example, 8 × 8 pixels, and the gradation values of the plurality of pixels in this block are two-dimensional discrete cosine transform (DCT conversion). ) DC as a conversion coefficient obtained by
Quantize the T coefficient using a quantization matrix, and then DC
The quantized coefficient obtained by quantizing the T coefficient is variable-length coded to obtain coded data.

The code data supply control unit 12 comprises a display condition designating unit 21, a control unit 22 and a code selecting unit 23.
Further, the image restoration unit 13 restores the original image from the DCT-transformed code data stored in the code data storage unit 11. The image restoration unit 13 has the configuration shown in FIG.

In the image restoration unit 13 of FIG. 4, the code data sent from the code selection unit 23 of the code data supply unit 12 in units of layers is first read into the variable length decoding unit 111 and using the decoding table 112. It is restored to a fixed length DCT coefficient. The DCT coefficient restored by the variable length decoding unit 111 is inversely quantized by the inverse quantization unit 113 by multiplication with the quantized coefficient from the quantization matrix 114, and the DCT coefficient is obtained.
It is converted into a coefficient and stored in the coefficient storage unit 115.

Here, 0 is stored as an initial value in the coefficient storage unit 115. Therefore, among the coefficients dequantized by the dequantization unit 113, only values other than 0 are newly added to the coefficient storage unit. Write to 115. After the variable length decoding and the inverse quantization of the coded data of the first layer of the selected image are completed, the DCT coefficient of the first layer of the selected image stored in the coefficient storage unit 115 is calculated by the inverse DCT transform unit 116. It is converted into gradation data and stored in the image storage unit 117. The image data stored in the image storage unit 117 is read by the image display unit 118, and the restored image is displayed on the monitor screen.

In this embodiment, as the image display section 118, two kinds of image display sections 118, which are an NTSC monitor and an HDTV monitor known as a high-definition television, are planned to be used. Next, details of the code data supply control unit 12 of FIG. 3 will be described. First, in the display condition designating section 21, for each of the image data A, B and C stored in the code data storing section 11, the NTSC monitor and H used in the image restoring section 13 are displayed.
A resolution data table indicating up to what level of code data to be supplied corresponding to the resolution of the DTV monitor is stored.

As the resolution data table stored in the display condition designating section 21, for example, the resolution data table shown in FIG. 5 is used. Specifically, the resolution data table itself of FIG. 5 is not stored in the display condition designating unit 21, and
As shown in, the resolution data table corresponding to each image is stored at the head of the hierarchical code data of the images A, B, and C stored in the code data storage unit 11. That is, at the head position of the code hierarchy data of the image data A, the first image A shown in FIG.
The third hierarchical level is stored as the number of hierarchical levels corresponding to the NTSC monitor, and the fourth hierarchical level is stored corresponding to the resolution of the HDTV monitor.

Here, assuming that the resolution data indicating the number of layers to be transmitted corresponding to the resolution of each monitor is 1 byte per monitor, a 2-byte resolution data table is added to the head of the layer code data in FIG. Will be. As described above, since the 2-byte resolution data table is added to the beginning of the hierarchical code data of the image data A, B, and C in the code data storage unit 11, the code selection unit 23 of the code data supply control unit 12 Therefore, when a specific image selection instruction is received from the control unit 22, the selected image, for example, the first 2 bytes of the image data A, is sent to the display condition designation unit 21 and the necessary hierarchy necessary for the NTSC monitor and the HDTV monitor. Create a resolution data table showing the numbers. Then, the data of the transition to the third byte, that is, the hierarchical code data is sequentially sent to the image restoration unit 13 in a hierarchical unit to restore and display the image.

FIG. 7 shows a state change associated with the code data supply control of the resolution data table provided in the display condition designating section 21 of FIG. First, in the initial state of FIG.
The required layers of the SC monitor (a) and the HDTV monitor (b) are empty data. When the display selection indicating the processing of the monitor used in the image restoration unit 13 is received from the control unit 22 side in this state, for example, the HDTV monitor (b) side sets the display condition as shown in the display selection state of FIG. It is specified as the designated information to be shown.

Subsequently, when the code selection unit 23 starts reading the selected image from the code data storage unit 11 according to an instruction from the control unit 22, it receives the first 2 bytes to which the resolution data table is added, For example, in the case of the first image A shown in FIG. 5, 3 is set as the required number of layers of the NTSC monitor (a), and 4 is set as the required number of layers of the HDTV monitor (b).

Control unit 22 of code data supply control unit 12
Receives, for example, an image selection instruction from the image restoration unit 13 side by the operator and type information of the monitor device to be used, issues an image selection instruction to the code selection unit 23, and obtains from the first 2 bytes of the code data by the image selection instruction. The required number of required layers is read from the display condition designating section 21, and the actual number of supplied layers in the third byte is compared with the number of specified layers corresponding to the resolution, and when the actual number of supplied layers reaches the specified number of layers. Will be instructed to select the next image.

FIG. 8 is a block diagram of an embodiment showing one embodiment of the controller 22 of FIG. In FIG. 8, the control unit 22
A resolution information setting unit 21 that sets resolution information indicating the NTSC monitor or the HDTV monitor from the image restoration unit 13 side.
1. An initialization unit 212 which performs an initialization process upon receiving a restoration start from the image restoration unit 13 according to an operator's instruction, and an image number storage unit 21 which stores an image number instructing a restored image.
3, a layer number storage unit that stores the restoration layer number of the selected image, a code selection instruction unit 25 that controls the code selection unit 23, an end determination unit 216 that determines the restoration end of the image, and a comparison unit 218.

To the input a of the comparison unit 218, the number of designated layers corresponding to the monitor type of the resolution information setting unit 211 of the resolution data table 220 provided in the display condition designation unit 21 is given, and to the input b. For example, the actually restored layer number stored in the layer number storage unit 214 is given.
Therefore, the comparison unit 218 compares the number of designated layers of the input a with the actual number of supplied layers of the input b, and is less than the number of supplied layers (a ≧ b).
If so, the layer number of the layer number storage unit 214 is incremented by one. On the other hand, when the layer number of the layer number storage unit 214 exceeds the number of layers specified by the resolution data table 220 (a <b), the image number of the image number storage unit 213 is incremented by 1, and at the same time, the layer number storage unit 214 is stored. The layer number is initialized to 1, and the next image is restored.

FIG. 9 is a flow chart showing the operation of the embodiment of the present invention shown in FIGS. 3, 4 and 8. In FIG. 9, first, in step S1, the resolution of the display device that outputs and displays the restored image, for example, specification information is received from the image restoration unit 13, and the resolution information setting unit 211 of the control unit 22 holds it. For example, as a display device of the image restoration unit 13, HD
When receiving the specification information of the TV monitor, information indicating the HDTV monitor is set in the resolution information setting unit 211. Further, the resolution information indicating this HDTV monitor is also supplied to the resolution data table 220 of the display condition designating section 21, and the resolution data table 220 in the initial state shown in FIG. 7 (1) is shown in FIG. 7 (2). The display selection state of the HDTV monitor (b) shown is set.

Subsequently, in step S2, the code selection unit 23 selects the image data A as the first image stored in the code data storage unit 11 according to the instruction from the control unit 22, and the supply to the image restoration unit 13 is started. At this time, the 2-byte resolution data table is added to the head of the code data 1-1 to 1-5 of the first image A as shown in FIG. The 2-byte resolution data table is extracted and displayed in the resolution data table 220 of the display condition designating section 21 as shown in FIG.
The number of layers required for C monitor 3 and the number of layers required for HDTV monitor 4 are set.

Subsequently, the first layer code data 1-1 of the first image A is selected in step S4, and the supply of the first layer code data to the image restoration unit 13 is started in step S5. The first layer code data of the first image A supplied to the image restoration unit 13 is converted into original image data by the image restoration unit 13 shown in FIG. 4 and displayed on the HDTV monitor of the image display unit 118. In the restored image of the first layer, an image having a rough image quality with respect to the resolution of the HDTV monitor is restored.

Subsequently, in step S6, the resolution data table 22
The required number of layers of the HDTV monitor stored in 0 = 4 and the current number of restored layers of 1 are compared, and since the required layers have not been completed, the process proceeds to step S7, and the layer number of the layer number storage unit 214 is incremented by one. Then, the next second layer code data 1-2 is selected, and the process returns to the supply of code data in step S5.

Similarly, the second layer code data 1-
The third and fourth layer code data 1-4 are supplied, and when the supply of the fourth layer code data 1-4 is completed, it is determined in step S6 that the number of layers 4 as a required layer has ended, and step S8 is performed.
Then, the existence of the next image is checked. In this case, since the image data B exists as the next image, step S8 is performed.
Then, the next image is selected by incrementing the image number of the image number storage unit 213 by one, and the process returns to step S2 and the same processing is repeated for the image data B of the code data storage unit 11.

When the restoration of the third image data C to the required number of layers is completed, it is determined in step S8 that the next image does not exist, and the end determination unit 216 outputs a specific end code to perform a series of restoration processing. Will come to an end.
In the above embodiment, the number of restoration layers required to obtain the resolution of the monitor used on the decoding side is determined at the head of the code data of the image stored in the code data storage unit 11. Although the resolution data shown is added, the resolution data table shown in FIG. 5, for example, is stored in advance in the display condition designating unit 21 of the code data supply control unit 12 without being added to the code data, and the monitor used on the code side is used. The required number of layers may be specified in the control unit 22 for each image by the specification information of.

Of course, the resolution data table for each image is added to the head portion separately for each image as in the above embodiment, and the resolution data table for all the images shown in FIG. 5 is stored as one data. After the resolution data table is read and set in the display condition designating section 21, the supply control of the decoded data of each image may be started. Further, although the above-described embodiment is an example of a so-called restoration device integrally including the code data storage unit 11, the code data supply control unit 12, and the image restoration unit 13 as shown in FIG. It goes without saying that the data supply control device 12 and the image restoration unit 13 may be connected by a communication line to perform data transmission between them.

In the above embodiment, the case where the NTSC monitor and the HDTV monitor are used has been described as an example.
It is obvious that the present invention is not limited to this, and can be realized by selecting a printing device such as a monitor and a printer or a plurality of printing devices having different resolutions. Further, although the above-described embodiment has been described with reference to the restoration of code data by DCT conversion, the present invention can be applied as it is to code data having an appropriate conversion method as long as the code data has a hierarchical structure. ..

[0039]

As described above, according to the present invention, the number of layers of code data corresponding to the resolution of the output display device on the restoration side is determined, and the code data up to the number of layers required to satisfy the resolution is determined. Since only the supply control is performed, the code data corresponding to the resolution required for output display can be supplied to restore the image without waste, and the code data can be efficiently transmitted to the restoration side in the image database search. be able to.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention.

FIG. 2 is a flowchart showing the operation of FIG.

FIG. 3 is a configuration diagram of an embodiment of the present invention.

FIG. 4 is a block diagram of an embodiment of the image restoration unit of FIG.

5 is an explanatory diagram showing the number of gradations supplied to the resolutions of the NTSC monitor and HDTV monitor for the first to third images shown in FIG.

6 is an explanatory diagram of a configuration of code data stored in a code data storage unit of FIG.

FIG. 7 is an explanatory diagram of a storage operation of the resolution data table of FIG.

8 is a configuration diagram of an embodiment of a code data supply control unit in FIG.

9 is a flowchart showing the operation of the embodiment of FIG.

FIG. 10 is a flowchart showing the operation of the conventional method.

FIG. 11 is an explanatory diagram of code data having a hierarchical structure.

[Explanation of symbols]

 11: code data storage unit 12: code data supply control unit 13: image restoration unit 21: display condition designation unit 22: control unit 23: code selection unit 111: variable length decoding unit 112: decoding table 113: dequantization unit 114 : Quantization matrix 115: Coefficient storage unit 116: Inverse DCT conversion unit 118: Image display unit 211: Resolution information storage unit 212: Initialization unit 213: Hierarchical number storage unit 214: Image number storage unit 215: Code selection instruction unit 216 : End determination unit 218: Comparison unit 220: Resolution data table

Claims (6)

[Claims] 1. An image data supply control method for supplying code data obtained by encoding an original image by dividing it into two or more layers, and code data storing code data of a plurality of images having a hierarchical structure. A storage unit 11, an image restoration unit 13 that restores an original image, and a code data supply control unit 12 that controls the number of layers of code data supplied from the code data storage unit 11 according to the resolution of the image restoration unit 13. An image data supply control method comprising: 2. The image data supply control system according to claim 2, wherein the code data supplied by the code data supply control unit 12 is transmitted to the image restoration unit 13 via a communication line. Image data supply control method. 3. The image data supply control method according to claim 1, wherein the code data supply control unit 12 restores up to what level the image data of one image is restored according to the resolution type at the time of image restoration. A display condition designating section 21 for designating the display condition, and a control section 22 for controlling the supply of code data by selecting the number of hierarchical layers corresponding to the resolution of the image restoration section 13 from the number of hierarchical layers designated by the display condition storing section 21. An image including a code selection unit 23 that selects corresponding code data from the code data storage unit 11 in hierarchical units under the control of the control unit 22 and sequentially supplies the selected code data to the image restoration unit 13. Data supply control method. 4. The image data supply control method according to claim 1, wherein the code data storage unit 12 stores layer number data indicating how many layers to restore according to the type of resolution at the time of image restoration. An image data supply control method characterized in that it is stored at the head position of the coded data of each image. 5. The image data supply control system according to claim 1, wherein the code data supply control unit 12 selects from among the layer number data at the head position of the code data read from the code data storage unit 11. An image data supply control method, wherein a target number of layers corresponding to the resolution of the restoration unit 13 is detected, and code data is supplied to the image restoration unit 13 in units of layers until the target number of layers is obtained. 6. The image data supply control method according to claim 1, wherein the code data storage unit 11 divides the original image into blocks each of which is composed of a plurality of pixels, and a plurality of pixels in the block are divided. The DCT coefficient obtained by the two-dimensional discrete cosine transform of the gradation value is quantized, and the quantized coefficient obtained by quantizing the DCT coefficient is encoded and stored as coded data of one image divided into a plurality of layers. The image restoration unit 13 restores the original image data by decoding the quantized coefficient from the coded data of the layer unit, dequantizing it, and converting it into the DCT coefficient, and further performing the inverse two-dimensional discrete cosine transform. Characteristic image data supply control method.