JPH0654941B2 - Image processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image processing apparatus, and in particular, image processing for inputting a plurality of pieces of first pixel information and converting the pieces of second pixel information into a smaller number of pieces of second pixel information than the input pixel information. It relates to the device.

[Prior Art] Conventionally, in this type of device, a majority operation is performed on a plurality of pieces of pixel information corresponding to one dot, and only one result is used to perform binarization of one dot.

For example, 1 dot corresponds to 4 image sensors,
In the conventional device that binarizes eight dots, as shown in (a) of FIG.
If two or more pieces of white information out of one piece of pixel information come, only a majority operation that makes the one dot white is performed independently for each dot, and binarization for eight dots is performed. It should be noted that FIG. 4A shows the correspondence between the dots D and the image sensor 1, and the numbers in the blocks are the dot numbers and the sensor numbers.

However, in the conventional device that performs such a process, as shown in FIG.
When the pixel information is read as shown in (b) and (c) (in the figure, the shaded area indicates black information), all 8 dots related to reading become black, and the image conveys white information. Despite the presence of the sensor, the obtained dot information is not reflected at all, and thus it is difficult to read the image faithfully to the original image.

[Purpose] The object of the present invention is to eliminate such a conventional defect, and when determining the image information of one dot, in addition to the majority operation of a plurality of pixel information corresponding to the dot, the image information of the dot adjacent to the dot By also considering the above, it is an object of the present invention to provide an image processing apparatus capable of more faithfully converting the image of a document into image information for each dot.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of the image processing apparatus of the present invention. Here, I is a reading head that optically reads an image on the original P, and has an image sensor array arranged in the sub-scanning direction so as to face the original surface. C is a carriage on which the reading head 1 is mounted, which is fixed on the conveyor belt B and can be moved in the scanning direction (S direction) along the guide rail G by the driving means M such as a step motor.

That is, the original image is read by the image sensor array arranged in the sub-scanning direction while the read head I moves in the S direction, and the read image information is shown in FIG. 2 (A).
It leads to the reading control section shown in.

FIG. 2 (A) shows an example of the configuration of the reading control unit which is the main part of the image processing apparatus of the present invention. Here, 1 is a self-scanning solid-state image sensor array such as a CCD, which has a light receiving element, a photoelectric converter for accumulating charges, a shift register, and the like. The size of the pixel of the light receiving element in the image sensor array 1 is sufficiently smaller than the size of the dot for reading and storing, and one pixel is composed of a plurality of pixels. In this example, one dot corresponds to four pixels.

The charges accumulated in the photoelectric conversion unit of the image sensor array 1 are transferred to the shift register unit, and then, for example, a central processing unit (hereinafter referred to as CPU) in a microprocessor type.
By the read signal RD from 2, the charge transferred to the shift register section is sent to the amplifier 3 and amplified. The output from the amplifier 3 is binarized via the binarization circuit 4, and the CPU2
And then stored in the first memory 5. CPU2 is a ROM that stores programs that perform the processing of majority voting and vertical comparison, and memory RAM for temporary storage required for the above processing.
Built in. Based on the data stored in the first memory 5, the CPU 2 determines the dot information by performing the processing described later with reference to FIG. 3 including the majority calculation and the comparison calculation with the upper and lower pixels, and determines the determined dot information. 2 Store in the memory 6.

FIG. 2 (B) is a diagram showing the contents of the temporary storage memory RAM provided in the CPU 2, where (-1), and
Four-pixel information corresponding to () and (+1) dots, and dot provisional information corresponding to (-1), (), and (+1) dots determined by a majority calculation to be described later in the B, D, and F areas. Is temporarily saved.

Next, in the image processing apparatus configured as described above, processing for converting pixel information from the image sensor 1 into dot information faithfully to the original image will be described. Here, as shown in FIG. 4 (a), a case will be described in which four pieces of pixel information are associated with one piece of dot information and eight dots are read. Further, as a majority calculation, when there are two or more pieces of white information among the four pixel information, it is assumed that the corresponding dot information is white.

FIG. 3 shows an example of the processing procedure of the read image by the apparatus according to the present invention. As described above, this procedure is stored in the ROM of the CPU2. In the figure, indicates the parameter of dot number.

First, in step S1, the information of four pixels corresponding to the first dot is read out and stored in area A of the temporary storage memory RAM, and in step S2 it is determined whether the number of white pixels is 2 or more. . Here, if the affirmative determination is made, the image information regarding the first dot (hereinafter referred to as the first dot information) is specified as white, and if the negative determination is made, the image information is specified as black and the information is stored in the second memory. Stored in 6 and
Save in area B of temporary storage memory RAM.

Next, in step S10, the parameter is set to "2", and in step S11, the information of the four pixels corresponding to the second dot is read out and stored in the C area of the temporary storage memory RAM.
In step S12, the same majority voting as in step S2 is performed, and based on the result, the second majority operation is performed in steps S13 and S14
The dot information is assumed to be black and white, respectively, and saved in the D area of the temporary storage memory RAM (the dot information assumed in this way is hereinafter referred to as second dot provisional information).

Next, in step S21, the second dot (+
1) Read out the 4-pixel information of the dot (third dot in this case) and store it in the E area of the temporary storage memory RAM, and through the steps S22-S24 similar to steps S12-S14, generate the (+1) th dot provisional information. Obtained and saved in the F area of the temporary memory RAM. Then, in step S30, the data stored in the B, D, and F areas of the temporary storage memory RAM (-
1) Dot information, provisional dot information, and (+1) th dot
It is determined whether all the dot provisional information (here, the first dot information, the second dot provisional information, and the third dot provisional information) are the same.

Here, if the determination is affirmative, it is determined in step S31 whether or not all the four pixel information corresponding to the second dot (here, the second dot) stored in the C area of the temporary storage memory RAM is equal, If even one pixel out of the four pixels has different information, the process proceeds to step S33, and the information obtained by inverting the temporary dot information is black if the temporary dot information is white, and white if black. Then, the inversion information is stored in the second memory 6 as the dot information. On the other hand, if there is different information among the three-dot information related to the determination in step S30 and if the determination is positive in step S31, the process proceeds to step S34, and the provisional information of the second dot (second dot in this case) is set. It is stored in the second memory 6 as the dot information.

Next, in step S40, it is determined whether or not +1 has reached 8. Since a negative determination is made here, step S41
Then, the value of is incremented by 1 and the process returns to step S21.

Hereinafter, similarly, the third to seventh dot information is determined. When = 7, an affirmative determination is made in step S40 and the process proceeds to step S42. Since there is no subsequent dot for the eighth dot, its provisional information Is directly determined as the eighth dot information and stored in the second memory 6.

Thus, by adding the upper and lower pixel comparison calculation to the majority calculation, as shown in FIG. 4, for example, in the case of (b) and (c) in the figure, all the dots are conventionally determined to be black. On the other hand, according to the present invention, in the case of (b), as in (d), in the case of (c)
Dot information is obtained as in (e). That is, the pixel information transmitted by the image sensor can be reflected in the dot information, and more faithful image information can be obtained from the original image.

In this embodiment, the number of dots and the number of pixels corresponding to one dot are set to 8 and 4, respectively, but these numbers are mere examples and can be arbitrarily set.

In the embodiment, the pixel information group for 8 dots is stored in the first memory and then the dot information determination process is performed. However, the pixel information group is sequentially transferred to the CPU in the process. May be performed at any time.

[Effects] As described above, according to the present invention, when determining the image information of one dot, in addition to the majority calculation of the pixel information group corresponding to the dot, each of the target dot and the dot adjacent thereto is determined. Considering whether the majority voting calculation results (second pixel information) are all equal, if they are equal, it is further determined whether or not the pixel information (first pixel information) groups forming the dot of interest are all equal, In the case of a negative determination, the majority calculation result of the target dot is inverted, so that there is an effect that an image processing apparatus capable of faithfully converting the original image into image information can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of the configuration of the image reading apparatus of the present invention, and FIGS. 2 (A) and 2 (B) are block diagrams showing an example of the configuration of an image reading control unit, which is the main part thereof. That CP
FIG. 3 is a diagram for explaining a temporary storage memory provided in U, FIG. 3 is a flow chart showing an example of an image reading processing procedure in the apparatus of the present invention, and FIG. 4 is an explanatory diagram for explaining an aspect of image reading according to the present invention. Is. I ... Read head, C ... Carriage, B ... Belt M ... Step motor, P ... Original, G ... Guide rail, 1 ... Image sensor, 2 ... CPU, 3 ... Amplifier, 4 ... Binarization circuit, 5, 6 ... memory.

Claims (1)

[Claims] 1. An image processing apparatus for inputting a plurality of pieces of first pixel information and converting the pieces of second pixel information into a number smaller than the number of pieces of input pixel information, wherein a majority decision operation is performed on the plurality of pieces of input pixel information. Regarding a pixel and a pixel adjacent to the front and rear of the pixel of interest, a majority calculation unit for calculating second pixel information, and second pixel information of the pixel of interest obtained by the majority calculation unit is adjacent to the pixel of interest. Changing means based on the second pixel information of the target pixel and the plurality of first pixel information used when obtaining the second pixel information of the pixel of interest, calculation by the majority decision calculating means, and change by the changing means. Control means for executing a change of the second pixel information every time the second pixel information is determined, wherein the changing means has the second pixel information of the pixel of interest and pixels adjacent before and after the pixel of interest. When all are equal, it is determined whether or not the plurality of first pixel information used when obtaining the second pixel information of the target pixel are all equal, and when the plurality of first pixel information are not all equal, The image processing apparatus is characterized in that the second image information of the pixel of interest obtained by the majority calculation means is inverted and output.