JPS5884358A - Picture enlargement processor - Google Patents

Abstract

PURPOSE:To obtain a magnified picture having the visual naturalness, by obtaining magnified image data at the coordinate position from the weight coefficient that is decided by the relation between the coordinate position and the position of the picture element of an original picture which encloses said coordinate position. CONSTITUTION:The weight coefficients S11-S22 which are delivered successively from a table memory 23 are multiplied by the picture element data f11-f22 of an original picture which are set to the registers 21a-21d. The results of these multiplications are fed successively to the adders 25a-25c to obtain the sum total. The value of this sum total is written to a prescribed picture element address of an output picture memory 3 in the form of a picture element data. This procedure is given to all picture elements of a magnified picture. Then the extracting region of the picture element data of the original picture is replaced. At the same time, the process is carried out repetitively until the data of all picture elements are obtained for a desired magnified image.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an image enlargement processing device that can obtain a natural enlarged image by linearly interpolating pixels of an enlarged image.

<Prior art and its problems> Recently, converting documents into files as images has been attracting attention. That is, using the calculation aIV stem, the sentence 1lIl!
Ii images are filed, searched and edited to speed up explosive charges and save labor. Then, dice the searched document images and various images! When displaying rays, I
[! There are many requests to enlarge and display only a desired area in an il image.

In this case, conventionally, the pixel data of the original image shown in Figure 1 (Hata) is repeatedly output according to the image enlargement ratio, and the second
An enlarged image as shown in Figure (b) is obtained.

This image enlargement process is very simple and can be realized exclusively from the viewpoint of the device configuration. However, @Figure 1・(a)(b)
As schematically shown, the enlarged (2) image is an enlarged version of the pixel size of the original image. For this reason, when there is a pattern of characters in a single document image, there is a problem in that the enlarged pattern turns into a so-called mosaic pattern, which is visually very unnatural. This problem became particularly noticeable as the magnification rate increased.

<Objective of the Invention> The present invention has been made in consideration of the above circumstances, and its object is to: 1. easily and effectively obtain an enlarged image with visual naturalness; The purpose of the present invention is to provide a highly practical enlarging treatment device that can be used in one place.

<Configuration of the Invention> The present invention calculates the coordinate position of the original image corresponding to one vote of the enlarged image, and uses a weighting coefficient determined by the relationship between this coordinate position and the surrounding original image pixel positions to calculate the original image. - Enlarged image data at the coordinate position is obtained from raw data. Then, this processing is performed in an iterative manner for reading out the data of one image of the original image, and the image data of the first enlarged image is obtained as required.

<Effects of the Invention> Therefore, according to the present invention, the expanded pixel data can be obtained from the pixel data of the original image by linear interpolation. Therefore, the data change in the 11ill interval adjacent to the enlarged image becomes smooth, and the overall visual result is 6:
The result will be a good one without any unnaturalness. Also, using four adjacent pixel data of the original image, enlarge 1i! corresponding to the chain ring surrounded by these vjIA elements! WA of II image circle element
Since the 7'''-events at the JIA position are sequentially obtained in a linear manner, it is possible to easily obtain the enlarged I[!II image r-events in Aimd, which has a great practical effect. become.

<Embodiment of the Invention> An embodiment of the present invention will be described below with reference to one drawing.

FIG. 2 is a schematic configuration diagram of the embodiment device. The input image memory 1 stores and stores the traces of the original image to be subjected to enlargement processing.
IIIIgr- It is constructed to bring out the evening light. The output-image memory 1 stores an enlarged image read from the input image memo 91 and outputs it to a display device (not shown) or the like. This output image memory J is
Writing and reading of the enlarged image data is executed under address control by the output address calculation circuit 4. These copying memories 1 and J (Dm1117') continued output and writing.

The 1aax enlargement process, which is performed synchronously under the control of the controller 5 and is used to enlarge the image data read from the input image memory 1 and write it in the output car image memo 97, is carried out by the 1a data calculation circuit 6. It is carried out from the second. This one-time data counting circuit 6 also operates under the control of the controller 5.

Now, in principle, the apparatus configured as described above executes image enlargement processing using linear interpolation as follows. Now, if we enlarge the original by three times, ζ; then, Figure 113 (1)
This will be explained with reference to (11). still.

Even if the enlargement ratios are different, basically the same processing can be performed. As shown in FIG.
When l* 'ml is shown, to enlarge it three times, each of the above images 1IE4-1t is shown in Figure (b).
t #' 11 I Divide the space between f□ and f0 into three equal parts, and divide 1l
liI elementary g.

Aki IN! 11g, f, and l were used as a standard.
ll.

g11* gts# Enlarged image IJ of gll to g18, totaling 9m! ! In order to obtain l elements, it is sufficient to consider the corresponding position coordinates on the original image. In other words, the enlarged image is 11! For the II element g1m, the original-image -element 'lls'l1 is 3
Divide it into equal parts, and consider the position coordinates of the side closer to the '11'. However, when the positional coordinates on the original image corresponding to each element of the enlarged image are determined in this way, each of these positional coordinates corresponds to the four pixels '11e'1m* of the original image according to the positional relationship. I□.

They each have a relationship with the data of ft1. That is, it is strongly influenced by the data of the pixel at the closest position, and is slightly influenced by the pixel data at a distant position. Therefore, if we capture this linearly.

The four coordinates '11 a 'l are spread over the two positional relationships.
According to the pixel data of le'IIg'□, it is possible to obtain image data of each linearly interpolated position coordinate.

Therefore, if we take the position coordinate gfil as an example, the relative distance to the pixel f is "1", -element f.

Distance against! II r2J, it is possible to obtain enlarged image data by linear interpolation, assuming that the data at the position m[gtm is the above-mentioned data. Also, -prime 'II 1'11
m 'IIs The position coordinates located inside the area surrounded by 'II, for example, the area divided by this position "11 * "11 # '11 s
Consider S, and these areas as a function of linear interpolation.

gom '11x811 +'ll''1m+'Hx8
Enlarged image data can be obtained as 11 +'**xtvs.

Therefore, according to the basic principle of image enlargement processing as described above, once the position coordinates on the original image corresponding to the pixels of the enlarged image are determined, the four two-dimensionally adjacent originals surrounding it can be found.
From the image pixel data, it is possible to obtain 1,000 enlarged image pixel values by linear interpolation processing.

However, in order to execute such enlargement processing, the platform controller 5 gives a command to the input address calculation circuit NI2, and specifies addresses of four two-dimensionally adjacent pixels in the input image memory 1.

The pixel data is successively sent to a density r-ta calculation circuit. At the same time, the controller 5 energizes the output address counting circuit 4, and calculates and calculates an enlarged 100 million art book having the 7th point i1 coordinate in the area surrounded by the 4 pixels consecutively output from the input image memory 1. ing. This negative address is specified to the output image memory 3 in the +11th order. Then, in the density data calculation circuit 6, the above output-image memory J is specified-
According to the pixel address, the image power of the pixel position is firstly determined by the linear processing described above.

. . . Fig. 4 shows an example of the configuration of the one-time data calculation circuit 6 that performs the image enlargement process using the linear interpolation described above. However, from Heker image memory 1, address calculation 1
For example, the four 1gX data calculated with 11'llj are shown in FIG. 5 (1).

Four registers are sequentially outputted in the order of Il*Il@"4 and connected as I! continuation two, j 2 bell
c, :Ildζ are stored sequentially. Also parallel 1; four registers 11a, jJb provided.

xxc, xxc4 2 are the table memory 11 force 1 and the area Ls s 811e sll * 8 @ @ l: 1
IIILz weighting coefficients are read and set. This weighting coefficient is used when the pixels of the output image memory 3 are specified in the order of 0leO1 to 0. shown in FIG. 5(b).

It changes according to the positional relationship of the pixel position coordinates in the designated order. In this image enlargement process of enlarging the image three times, %the register 21 is used.

21b, xi town, and 9 for the four cumulative data '11*'lle 'ml p'- set in 21d.
[Weighting coefficients are sequentially output from the table memory 2J force 1 over the timing, and the weight coefficients are sequentially output from the registers 221゜11b, 12c, 1.
2tli: Set. Such a weighting factor 5lls
'lyoB'11 e a,, ha.

When the magnification rate is "3", 1 is determined, for example, as follows.

And the above-mentioned registers I1m, Ilb, and 12c.

The weighting coefficients shown in the above table that are sequentially set in Jjd are multipliers 14 m , 14 b , j4c.

24-, respectively, and the register 21m.

1IjI set to 21b, 21c, 11-! ll
The image is divided into pixel data. And so(D
ME calculation result is addition @jja, Is b, 25
c4''l- are given sequentially and the sum is determined. This sum value is written to a predetermined pixel address of the output-image memory 3 as pixel data of the enlarged image.

For example, at timing T4, when the corresponding T6ff weighting coefficient (V3, 0, 1/3, O) is output to the output mx address 0, the multiplication process and the summation process of the multiplication results are performed according to this weighting coefficient. Then, pixel data for the pixel address 04 is obtained, and this data is written to the pixel address 04 of the output image memory 3.

After such image enlargement processing is performed on all the pixels of the enlarged image based on the pixel data '11*'Its 'l1w'□ of the original image, the pixel data of the original image is For example, the extraction area of pixel data is '11 * '18 m 'II m '1
m, and image enlargement processing is similarly performed using these as a reference. Thereafter, the above-described process is repeated until data for all pixels of the desired enlarged image is obtained.

Note that the above-mentioned weighting coefficients over the nine timings are an example when the image magnification rate is 3 times, but the gradation coefficients may be similarly given even in the case of other magnification rates. In general, the weighting coefficient may be calculated and used each time the opening address of the enlarged image is determined.

Figure @6 explains the principle of linear interpolation for providing easting coefficients. l1m consisting of enlarged 1ilI image
Once the positional coordinates on the original image corresponding to one element are determined, the positional relationship between the positional coordinates and the pixel address of the original image is uniquely determined. In other words, as shown in Figure 6,
! When the iI#g interval is "1" and the position coordinates of the enlarged image are (ΔX, Δy) with the upper left pixel as a reference, the ratio of the inter-pixel unit surface structure divided by this positional tilt is:

8m, :=ΔX・jy 8□=(1−jx)・jy 83聰=ΔX・(l−Δy)S□=
It is calculated as (1-ΔX)・(l-jy). Therefore, based on this surface m ratio, for example, it is assumed that the r-value of the position coordinates (ΔX, Δy) is determined by being influenced by the data of each pixel of the original image at a ratio corresponding to its reciprocal. , linear interpolation will be performed here. Therefore, as shown in Figure 87, when the position coordinates (x, y) of the enlarged image with respect to the original image are determined, its decimal part (jx) (jy) and the corresponding auxiliary value (1-)x) After calculating s(1jy), 1 multiplier 16
m, R1b, l1lc.

The area values '1168□, 8□°, and 8I may be obtained through 26d. and.

If the primary weighting coefficient is determined according to the distribution ratio of these area values, image enlargement processing can be performed for any enlargement ratio.

As described above, according to this device, the pixels of the enlarged image are sequentially determined by linear interpolation with respect to the original image, so that the enlarged image is visually natural and reflects the characteristics of the original image. It becomes highly sexual. In addition, the image enlargement process can be performed very easily as described above, and can be performed at high speeds in a short time. In other words, the source that forms the basis of the data.
After obtaining the pixel data of the image and calculating all the pixel data of the enlarged image obtained from this, the process moves to image enlargement processing based on the next pixel data, so the calculation processing speed is fast. Therefore, it is possible to achieve effective enlargement 1Ii1111 without impairing visual naturalness, and its practical advantages are enormous.

Note that the present invention is not limited to the above embodiments. For example, the image enlargement rate can be set arbitrarily, lol! It is not specified by Ii1 times. In addition, address calculation circuits 2 and 4
The configuration and the configuration of the concentration data needle line circuit 6 can also be modified in various ways depending on specifications. In short, the present invention can be implemented with various modifications without departing from its gist.

[Brief explanation of drawings]

441 (a) and (b) are diagrams showing the concept of conventional image enlargement processing, and Fig. 2 shows an embodiment of the present invention.
fII4 diagram, @3 Figures (a) and (b) are diagrams showing the concept of image enlargement processing according to the present invention, and Figure 4 is the density r of the embodiment device.
- Diagrams showing an example of the configuration of a data calculation circuit, FIGS. 5(a) and (b)
6 is a diagram for explaining the concept of weighting coefficients, and FIG. 7 is a diagram illustrating the process of calculating weighting coefficients. DESCRIPTION OF SYMBOLS 1... Input image memory, 2... Input address calculation circuit, 3... Output image memory, 4... Output address calculation circuit, 5... Controller, ---Density data calculation circuit, IIs, Ilb, II@, 114” register (
original image data), Ila, Ilb. 11e, Ild... register (weighting coefficient), 21...
・Table memory, 14m, 14b, 14@. x J m-multiplier, 2ja, Ilb, 21cm adder, Ila, Ilb, j#c, 1g4-* multiplier. Applicant's agent Patent attorney Suzu Jiang Wu Liao Figure 1 Figure 3 114m! 1 Sip-1, l Fig. 5 (a) (b) Fig. 6 522 521 'z12Su

Claims (1)

[Scope of Claims] An input image memory that stores an original image, and an output image memory that stores an enlarged image that has been subjected to enlargement processing. Means for calculating a screen position on the original image corresponding to each llljIll position of the output image memory according to an image enlargement ratio; and means for calculating pixel positions of the image surrounding the calculated one-plane position. and a data calculation circuit that calculates enlarged image data at the -plane position from the original image data at each pixel position using weighting coefficients determined according to the positional relationship between these calculated pixel positions and the -plane position. An image enlargement processing 3I device characterized by: