JPH01150983A - Picture processor - Google Patents

Abstract

PURPOSE:To obtain a satisfactory output picture at least up to magnification corresponding to picture elements to be interpolated by interpolating between the respective picture elements when an original picture is inputted. CONSTITUTION:Picture data 20 outputted from a picture reading part 1 are developed as picture data 21 to an buffer, which is not illustrated, in an interpolation processing part 2. At this time, since the number of clocks to the interpolation processing part 2 is twice as many as that to the picture reading part 1, the picture data 20 are developed alternately as illustrated. Next, while the picture data 21 are developed to a picture memory 3 according to an address generated with the number of the clocks of a.2.fW, the picture data 21 are read from the picture memory 3 according to another address generated with the number of the clocks of b.fR and outputted to an external part with the number of the clocks of fW. When pictures twice as many or more are to be obtained, the desired number of pictures can be achieved by fixing (a) to '1' and changing (b) within the range of '0<b<1'. The enlargement ratio at this time becomes 1/b.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image processing device, particularly an image processing device that uses an image processing device after reading an original image.
The present invention relates to an image processing device that outputs images at variable magnification.

[Prior Art] Normally, when a read original image is subjected to scaling processing and output, the original image is temporarily stored in a memory, and then processed by changing the number of clocks or the interval at which it is read from the memory. many.

For example, when an image is stored in the image memory, if pixel data is read every other pixel in the main scanning and sub-scanning directions and then output (so-called thinning processing), the resulting output image will be The vertical and horizontal values are % (area and area) of that in the image memory. Generally, by increasing the reading speed (address update speed) from the image memory and outputting the pixel data using the reference clock, it becomes possible to output an image with a reduction ratio relative to the reading speed.

On the other hand, when trying to obtain twice the output image, for example,
Conversely, processing is performed in which the speed of reading from the image memory is reduced and output is performed using the reference clock. For example, if the reading speed is set to the reference clock, the same pixel will be
This is equivalent to reading the same pixel twice, and the same pixel is output twice in a row.

This is a so-called pixel increase.

[Problems to be Solved by the Invention] However, when trying to form an enlarged image using such scaling processing, each pixel stored in the image memory is This causes a problem in that an image that looks rough is output.

The present invention has been made in view of such prior art, and by interpolating between each pixel when inputting a document image, it is possible to obtain a good output image at least up to the magnification corresponding to the interpolated pixel. The purpose of this invention is to provide an image processing device that is well-accepted.

[Means for Solving the Problem] In order to solve this problem, the present invention includes the following configuration.

That is, an input means for manually inputting digital multi-gradation pixel data, an interpolation means for interpolating at least one pixel between the input pixel data, and image data composed of the interpolated pixels and input pixel data. a first clock control means for controlling the number of storage clocks when storing the image data in the storage means; a reading means for reading the image data stored by the storage means; and a reading means for reading the image data stored by the storage means. and second clock control means for controlling the number of clocks for reading by the means.

[Operation] In the configuration of the present invention, the pixel data input by the input device is interpolated by the interpolation device, and the image data is stored with the number of storage clocks determined by the first clock control device. Further, the image is read and outputted using the number of reading clocks determined by the second clock control means.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Explanation of the outline of the structure (FIG. 1)> FIG. 1 is a schematic diagram of the structure of the image processing apparatus in the embodiment.

In the figure, reference numeral 1 denotes an image reading section that reads an original image, and outputs 8-bit data (1 byte=256 gradations) in accordance with the optically read pixel density. 2 is an interpolation processing unit that interpolates between pixel data output from the image reading unit 1, and 3 is an image memory that reads and stores pixel data from the interpolation processing unit 2 (in the embodiment, it is configured with a dual port memory). It is. 4 is a clock generator circuit, in which the number of clocks is fw for the image reading section 1, twice that number fw for the interpolation processing section 2, and the clock for writing data to the image memory 3 is a variable clock circuit. The clocks of a, 2, and fw are outputted through the clocks 5 and 5, respectively. Note that in the clock generated from the variable clock circuit 5, O<a≦1, and this change is set by the switch 8.

Reference numeral 6 denotes a clock generation circuit that generates a clock of frequency fR, which is used for image output and is outputted to the clock variable circuit 7. Similar to the variable clock circuit 5, the variable clock circuit 7 changes the frequency bf, based on the setting with the switch 8.
The clock is used as the generation timing of the read address from the image memory 3. However, 0 b≦1.

Description of Interpolation Processing (Fig. 2)> The processing contents of the interpolation processing section 2 in the above-described configuration will be explained with reference to Fig. 2.

Image data 20 output from the image reading section 1 is developed as image data 21 in a buffer (not shown) within the interpolation processing section 2. At this time, since the number of clocks to the interpolation processing section 2 is twice that of the image reading section 1, every other clock is expanded as shown. In the interpolation processing unit 2, a one-row matrix 22 (sinc
The image data 23 is obtained by calculating the "°0" data in the image data 21, that is, the pixel density at even addresses.

For example, the pixel density Cn+2 is: Cn+2 = a n't) - s+ a y1
+1”b −3+ a n+2°b−.

"a n+3' b +"a r1+4' b 3"a
n+5" b 5=50・0.127+200・(-
0,212) 4200・0.637+50・0.637
+20・(-0,212)+20・0.127#121
becomes.

Furthermore, other Cn+k can also be determined by similar calculations.

Explanation of magnification processing> Now, after the above-mentioned interpolation processing (processing of doubling the input image and interpolating between each pixel), the number of clocks is a
・2・f is developed in the image memory 3 according to the address generated by f, and the clock number is read from the image memory 3 according to the address generated by b−fR,
It is output to the outside (for example, a laser beam printer or a display device) at the clock number fw.

Therefore, when trying to output an image that is the same size as the original image, it is sufficient to set a = 0.5 and b = 1. When trying to obtain a reduced image, b is fixed to "1" and a is set to “O<
If it is changed within the range of a<0.5'', an image with a reduction ratio of 2·a is formed.

Also, when trying to obtain an image from 1x to 2x, b can be fixed at 61'' and a can be varied within the range of 0.5 x a≦1 (the magnification is 2 x a Note that during this period, at least, the problem that the image becomes rough due to enlargement does not occur.

Now, if you want to obtain an image that is more than twice as large, change a to “
This can be achieved by fixing i'' and varying b within the range of °'O<b<1''. The magnification ratio at this time is 1/b.

As explained above, according to this embodiment, it is possible to obtain an image with a desired magnification with a simple configuration,
Since it is sufficient to output an image interpolated by the interpolation process up to at least twice the size of the image, there is no possibility that the image will deteriorate when enlarged to less than twice the size.

Furthermore, since the interpolation process is performed by simple calculations with data in a table, the interpolation process becomes faster.

Incidentally, in the above-described embodiment, both the frequency coefficients a and b changed by the switch 8 were set to "1" or less, but for example, if a="1"
'', and if b can be changed to a value larger than 1, it is possible to achieve a similar variable magnification output.

Further, in the embodiment, the interpolation processing unit 2 inserts one pixel between each pixel of the input image, and calculates the density of the inserted pixel. However, for example, if the number of inserted pixels is 2
It is perfectly fine to have more than two. In this case, the same effect can be achieved by changing the matrix 22 based on the sinc function, but if two pixels are inserted, for example, it is possible to output a good image up to a 3x magnification.

[Effects of the Invention] As described above, according to the present invention, it is possible to obtain an image with a desired magnification with a simple configuration, and at least the magnification of the image obtained by interpolation processing is good. This makes it possible to form images with a wide range of colors.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the main components of an image processing apparatus in this embodiment, FIG. 2 is a diagram for explaining the contents of interpolation processing in this embodiment, and FIG. 3 is a diagram illustrating the contents of a conventional enlarged image. In the figure, 1... image reading section, 2... interpolation processing section, 3...
...Image memory, 4.6...Clock generation circuit, 5.
F...Clock variable circuit, 8...Switch. Figure 2

Claims (2)

[Claims] (1) Input means for inputting digital multi-gradation pixel data; interpolation means for interpolating at least one pixel between the input pixel data; and image data composed of the interpolated pixels and input pixel data. storage means for storing the image data; first clock control means for controlling the number of storage clocks when storing the image data in the storage means; and reading means for reading the image data stored by the storage means. and second clock control means for controlling the number of clocks for reading by the reading means. (2) The gradation level of the dummy pixel interpolated by the interpolation means is s
2. The image processing apparatus according to claim 1, wherein the image processing apparatus also performs calculation using a table based on an inc function.