JPS61201560A - Image reader - Google Patents

Abstract

PURPOSE:To convert an original picture into picture information at every dot with fidelity by taking the picture information of an adjacent dot in deciding one dot picture information into account in addition to majority operation of plural picture information corresponding to the dot. CONSTITUTION:An electric charge stored in a photoelectric conversion section of an image sensor array 1 is transferred to a shift register section, then the electric charge transferred to the shift register section is sent to an amplifier 3 by using a read signal RD from a CPU 2 of e.g., a microprocessor form and then amplified. An output from the amplifier 3 is binary-coded via a binary coding circuit 4 and sent to the CPU 2 and stored in the 1st memory 5. The CPU 2 applies processing including majority operation and comparing operation with upper and lower picture elements based on a data stored in the 1st memory 5 to decide dot information and stores the decided dotinformation to the 2nd memory 6. Thus, in adding the upper/lower picture element comparing operation to the majority operation in this way, it is possible to reflect the picture element information sent from the image sensor onto dot information and the picture information with fidelity to the original picture is obtained.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to an image reading device, and in particular, it has a plurality of pixel information reading elements (image sensors) corresponding to one unit of image area (dot), and The present invention relates to an image reading device that obtains one dot's image information from a plurality of pieces of pixel information.

[Prior Art 1] Conventionally, in this type of device, a majority calculation is performed on a plurality of pieces of pixel information corresponding to one dot, and one dot is binarized using only the result.

For example, if four image sensors correspond to one dot,
In the conventional device that performs binarization on 8 dots, as shown in Fig. 4 (a), if two or more of the four pixel information for one dot to be binarized come with mortar information, the corresponding one
Only a majority calculation such as making a dot white was performed independently for each dot, and 8 dots were binarized. In addition,
FIG. 4(a) shows the correspondence between dots D and image sensors I, and the numbers in the blocks are the dot numbers and sensor numbers.

However, in conventional devices that perform such processing, when pixel information is read as shown in FIGS. Even though some image sensors are transmitting white information, it is not reflected in the obtained dot information at all, making it difficult to read the image faithfully to the original image. There was a drawback.

[Objective] An object of the present invention is to eliminate such conventional drawbacks, and when determining the image information of one dot, in addition to the majority calculation of a plurality of pieces of pixel information corresponding to the dot, the image information of the dot adjacent to the dot is determined. It is an object of the present invention to provide an image reading device that can more faithfully convert a document image into image information for each dot by taking information into consideration.

[Example 1] The present invention will be described in detail below with reference to the drawings.7 Figure 1 shows an example of the configuration of an image reading apparatus of the present invention. It is a reading head for reading, and has an image sensor array arranged in the sub-scanning direction facing the document surface.

Reference numeral C denotes a carriage on which the reading head 1 is mounted, which is fixed on a conveyor belt B and is movable in the scanning direction (S direction) along a guide rail G by a driving means M such as a step motor.

That is, the document image is read by an image sensor array arranged in the sub-scanning direction while the reading head moves in the S direction, and the read image information is transferred to the image sensor array shown in FIG.
) to the read control section.

FIG. 2(A) shows an example of the configuration of the reading control section which is the main part of the image reading apparatus of the present invention, where l is a self-scanning solid-state image sensor array such as a CCD, a light receiving element,
It has a photoelectric conversion unit that accumulates charge, a shift register, etc. The size of the pixel of the light receiving element in this image sensor array 1 is sufficiently small compared to the size of the dot related to reading and storage, and one dot is made up of a plurality of pixels. In this example, one dot corresponds to four pixels.

The charges accumulated in the photoelectric conversion section of the image sensor array l are transferred to a shift register section, and then transferred to the shift register section in response to a read signal RD from a central processing unit (hereinafter referred to as CPU) 2 in the form of a microprocessor, for example. The generated charges are sent to the amplifier 3 and amplified.

The output from the amplifier 3 is converted into a z-value via the binarization circuit 4, sent to the CPU 2, and then stored in the first memory 5. The CPU 2 includes a ROM in which programs for processing majority calculations and upper/lower comparison calculations are stored, and a temporary storage memory RAM necessary for the above processing. Based on the data stored in the first memory 5, the CPU 2 determines dot information by performing the processing described later with reference to FIG. 3, including majority calculation and comparison calculation with the upper and lower pixels. 2 and stored in memory 6.

FIG. 2(B) is a diagram showing the contents of the temporary storage memory RAM provided in the CPU 2, and areas A, C, and E each have (
Four pixel information corresponding to u-1), (fL), C sentence +1) dots were determined in the B, D, and F areas by the majority calculation described later (see-1).

(1), (fL+1) Temporary dot information for the dot is temporarily stored.

Next, a process for converting pixel information from the image sensor 1 into dot information faithfully to the original image in the image reading apparatus configured as described above will be described.

Here, as shown in Figure 4(a), four pieces of pixel information are
A case will be explained in which eight dots are read in correspondence with one dot information. Furthermore, as a majority calculation, if 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 image reading processing procedure of the apparatus according to the present invention, and as described above, this procedure is stored in the ROM of the CPU 2. In the figure, beans indicate parameters of dot numbers.

First, in step Sl, the 4th dot corresponding to the first dot is
The pixel information 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 determination is positive, the image information regarding the first dot (hereinafter referred to as the first dot information) is specified as white, and if the determination is negative, it is specified as black and the information is stored in the second memory. 6 and also saves it in area B of the temporary storage memory RAM.

Next, in step S10, the parameter statement is set to 2'',
After reading the information of the 4 pixels corresponding to the second dot in step Sl+ and storing it in the C area of the temporary storage memory RAM, in step S12 a majority calculation similar to that in step S2 is performed, and based on the result, the step In S13 and S14, the second dot information is assumed to be black and white, respectively, and stored in the D area of the temporary storage memory RAM. To tell).

Next, in step S21, the n+1th dot is integrated into the first sentence dot.
) Read out the 4 pixel information of the dot (in this case, the third dot) and save it in the E area of the temporary storage memory RAM,
Steps S22 to S24 similar to steps S12 to S14
Then, the (ll+1)th dot temporary information is obtained and stored in the F area of the temporary storage memory RAM. Memory RAM for F (7) if/1111 stored in B, D, and F areas
1) Dot information, temporary dot information, and
+1) Determine whether the temporary dot information (here, the first dot information, the second temporary dot information, and the third temporary dot information) are all equal.

Here, if the determination is affirmative, the process goes to Step S31, where the number 7 stored in the C area of the temporary storage memory RAM is
It is determined whether all four pixel information corresponding to the dot (in this case, the second dot) are equal or not, and if there is different information for even one pixel among the four pixels, the process proceeds to step 333, and the temporary intersecting dot information is inverted. If the changed information, that is, the tentative alternating dot information, is white, it is set to black, and if it is black, it is set to white, and the inverted information is stored in the second memory 6 as the second alternating dot information. On the other hand, if there is different information among the information on the 3 dots related to the determination in step S30, and in the case of an affirmative determination in step S31, the process advances to step S34, and the third intersecting dot (in this case, the second dot) is determined. )4Fi information is stored in the second memory 6 as the first dot information.

Next, in step 940, it is determined whether or not the count +1 has reached 8, and since a negative determination is made here, step S
The process advances to step S41, increments the value by +1, and returns to step S21.

Thereafter, information on the 3rd to 7th dots is determined in the same manner, and when the result is 7, an affirmative determination is made in step S40 and the process proceeds to step S42, and as for the 8th dot, since there is no subsequent dot, The temporary information is determined as the eighth dot information and stored in the second memory 6.

In this way, by adding the upper and lower pixel comparison calculation to the majority calculation, as shown in FIG.
In cases such as (C) and (C), conventionally all dots were determined to be black.

According to the present invention, dot information can be obtained as shown in (d) in the case of (1+), and as shown in (e) in the case of (C). In other words, it is now possible to reflect the pixel information transmitted by the image sensor in the dot information.
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 merely examples, and it goes without saying that they can be set to any desired number.

Furthermore, in the embodiment, the dot information determination process is performed after all the pixel information groups for 8 dots are stored in the first memory, but in the process in which the pixel information groups are sequentially transferred to the CPU, It may also be done in the following manner.

[Effect 1] As explained below, 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 that dot, the image information of the dots adjacent to the dot is also taken into consideration. Therefore, it is possible to realize an image reading device that can more faithfully convert a document image into image information.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the configuration of the image reading device of the present invention, and FIGS. 2(A) and 2(B) are block diagrams showing an example of the configuration of the image reading control section, which is the main part thereof. FIG. 3 is a flowchart showing an example of an image reading process procedure in the apparatus of the present invention, and FIG. 4 is a diagram for explaining an aspect of image reading according to the present invention. It is an explanatory diagram. ■...reading 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] In an image reading device having a plurality of pixel information reading elements corresponding to one unit of image area, a majority operation is performed on the plurality of pixel information read by the plurality of pixel information reading elements to obtain one corresponding unit of image area. majority decision calculating means for provisionally determining image information of the one unit image area, and determining image information of the one unit image area by comparing and calculating the temporarily determined image information with image information of an image area adjacent to the one unit image area. 1. An image reading device comprising: comparison calculation means for performing a comparison operation.