JPS63285064A - Photometric method - Google Patents

Abstract

PURPOSE:To decide a proper binarizing level in a short arithmetic time by sectioning plural picture elements into plural picture element blocks comprising adjacent plural picture elements and extracting a signal intermittently from each of the plural picture element blocks so as to apply photometry. CONSTITUTION:A line sensor 42 consists of the series arrangement of plural picture elements 1, 2, 3...n, and they are used while being sectioned into plural picture element blocks taking the plural adjacent picture elements as one unit. In applying photometry to the body subject to photometry, the line sensor 42 and an object subject to photometry are moved relatively and while executing sub scanning, a signal is extracted from each of picture element blocks intermittently. Thus, the specific area of the body subject to photometry is measured simultaneously for each picture element block, and the specific area made correspondent to the length of one character and the picture element number constituting the picture element block is decided corresponding to the length, then the bright tendency of one character is subject to photometry.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a photometric method for image recording media, etc., and in particular, by reading character information etc. recorded on a photometric object such as a microfilm or paper. The present invention relates to a photometry method used when determining a binarization level when binarizing and recording on a digital recording medium such as a tape.

[Conventional technology]

Recording media used in filing OA (office automation) can be mainly classified into analog recording media such as microfilm and digital recording media such as optical discs.

By the way, this filing OA is capable of inputting large amounts of information in a coherent manner, high-speed duplication, legal evidence, long-term preservation, uniformity of recording media standards, high resolution, high recording density, high-speed searching, linking with communication networks, and instant processing. (No need for development or fixing with processing liquid and can be read immediately after writing)
, ease of addition and update, and other characteristics are required. It is difficult to have all of these characteristics, and both analog recording media and digital recording media have advantages and disadvantages.

It is necessary to complement each other with the characteristics of the image recording media.
For this reason, an optical/micro integrated file system has been proposed (for example, 1-Microgranoics J
December 1000 issue, pages 17 to 22, Applied Mechanical Engineering J July 1984 issue, pages 76 to 81, JP-A-59-64855, JP-A-59-638
Publication No. 60).

However, when converting a microfilm file to an optical disc, the operator must manually input search information, and the reading information required for image reading must be set in advance, which reduces the operating efficiency of the optical disc recording device. not good.

Therefore, the present applicant has already proposed an image processing method that can read images recorded on microfilm and efficiently record them digitally on a digital recording medium (Japanese Patent Application No. 61-1478E15). , patent application 1986-147
No. 886, Patent Application No. 162566, Patent Application No. 1983-
No. 165093).

When converting analog data into digital data using the above image processing method, a line sensor with 5,000 1/16 x 16 m pixels arranged in series is used, and an electric current is applied in the pixel arrangement direction of the line sensor. In addition to performing this main scanning, the line sensor and the photometric object are moved relative to each other in a direction perpendicular to the pixel arrangement direction to perform sub-scanning to scan the entire frame of the microfilm, and the data is recorded in memory and displayed. The binarization level is determined by performing n processing.

In this way, the purpose of determining the binarization level using a line sensor is to improve the quality of the image depending on the format of the character information (Mincho typeface, Gothic typeface, etc.) recorded on the photometric object such as microfilm. This is because the binarization level for reading is different.

[Problem that the invention seeks to solve]

However, in the above method, all the pixels of the line sensor are used to scan the entire surface of the photometric object, which requires a large number of memories, making the entire device expensive. Since the binarization level is determined by , there is a problem that the calculation time becomes long.

The present invention was made in order to solve the above problems, and an object of the present invention is to provide a photometry method that can determine an appropriate binarization level in a short calculation time using an inexpensive device.

[Means for solving problems]

To achieve the above object, the present invention involves relatively moving a line sensor in which a plurality of pixels are arranged in series and a PIl photometer to perform sub-scanning while extracting signals from the line sensor to perform main scanning. When photometrically measuring a photometric object, the plurality of pixels are divided into a plurality of pixel blocks each consisting of a plurality of adjacent pixels, and a signal is intermittently extracted from each of the plurality of pixel blocks for photometry. do.

[Effect]

The line sensor used in the present invention is configured by arranging a plurality of pixels in series, and the plurality of pixels are used by being divided into a plurality of pixel blocks each having a plurality of adjacent pixels as one unit. . When photometrically measuring a photometric object using this line sensor, photometry is performed by intermittently extracting signals from each pixel block while performing sub-scanning by moving the line sensor and photometric object relative to each other. .

Since the photometered object is photometered for each pixel block, it is possible to simultaneously measure a specific area of the photometered object for each pixel block.For example, this specific area can be made to correspond to the length of one character, and By determining the number of pixels constituting a pixel block in accordance with this length, it is possible to photometer the brightness trend of one character. In addition, since signals are intermittently extracted from each pixel block, the amount of data is smaller than when measuring the entire surface of the object to be photometered using all pixels. 2 in hours (
11! You can determine the level of In the present invention, it is also possible to perform photometry in a substantially diagonal direction of a rectangular photometric object by intermittently extracting signals sequentially from each pixel block from one end of the line sensor to the other end. In addition, pixel blocks may be preferentially selected and photometered in areas with high image density according to the image density of character information etc. recorded on the photometered object, and further pixel blocks may be It is also possible to randomly select and measure light.

〔Effect of the invention〕

As explained above, according to the present invention, since signals are intermittently extracted from each pixel block consisting of a plurality of adjacent pixels for photometry, it is not necessary to scan the entire surface of the object to be photometered using all pixels. Photometry that reflects the shape of the entire photometer is possible.

In addition, the binarization level can be determined by processing the information of about one line sensor, which makes it possible to determine the appropriate binarization level in a short calculation time using inexpensive equipment. This effect can be obtained.

[Explanation of aspects]

Next, aspects of the present invention will be explained. In carrying out the present invention, the following embodiments may be adopted.

In the first method a, the plurality of pixel blocks are divided into subsequent and subsequent pixel block groups, one pixel block group is sequentially selected 8J6 from the plurality of pixel block groups, and the selected pixel block group is In this system, signals are extracted from pixel blocks belonging to the pixel block and photometered.

According to this aspect, one pixel block group is sequentially selected from a plurality of pixel block groups, and signals are extracted from pixel blocks belonging to the selected pixel block group. The photometry is divided into SRbt in advance, and 1illii cumulative block groups are determined corresponding to these photometry fiI regions (this makes it possible to perform photometry for each photometry area. For example, by calculating the weighted average value from the data of each photometry area, By performing calculations, it becomes possible to calculate the binarization level with a weight attached to a specific photometric area.In addition, a histogram is obtained based on the data from each pixel block group, and the binarization level is calculated from a specific point. You can also decide.In this way,
The binarization level can be determined effectively even when image information is recorded in a biased manner on the photometric object.

Further, in a second aspect, the plurality of pixel blocks are arranged as a first pixel block group at intervals of one pixel block;
A pixel block group that is not included in the first pixel block group is divided into a second pixel block group and a third pixel block group, which are divided into two in a direction perpendicular to the pixel arrangement direction, and the pixel block group is divided into a second pixel block group and a third pixel block group, and Extracting a signal from one pixel block belonging to the group and extracting a signal from one pixel block belonging to the second pixel block group
After alternately extracting signals from one pixel block belonging to the first pixel block group and extracting signals from one pixel block belonging to the third pixel block group, In this method, photometry is performed by alternately extracting and extracting signals.

In this aspect, a pixel block group arranged at one pixel block interval is defined as a first pixel block group, and each group obtained by dividing the pixel blocks not included in the first pixel block group into two in the pixel arrangement direction is divided into two groups. After alternately extracting signals from the first pixel block group and the second pixel block group as the second pixel block group and the third pixel block group, the signals are extracted from the first pixel block group and the third pixel block group. The signals are taken out alternately. Therefore, by sequentially extracting signals from the pixel blocks of each pixel block group from one end of the line sensor to the other end, the first pixel block group performs photometry in a substantially diagonal direction of the photometered object.

Further, a direction substantially along the diagonal line of each region divided into two by the diagonal line of the photometered object is photometered by the second pixel block group and the third pixel block group. by this,
The entire photometered object is photometered approximately uniformly, and a binarization level that evaluates the entire photometered object approximately uniformly can be determined.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, an overview of a file conversion system to which the present invention is applied will be explained with reference to FIG.

A document 10 is photographed by a camera 12, and a readable microfilm 16 is created from the exposed microfilm through a processing process 14 such as development, fixing, and washing.
There are 18.35m roll microfilm 20, microfiche 22, aperture card 24, and so on.

When photographing on microfilm, move camera 12 to document 10.
Since the document 10 can be carried out to a place where it is present and there is no need to take the document 10 out, confidentiality is excellent and loss of the document can be prevented.

In addition, creating microfilm is faster than inputting to an optical disc (for example, 5,000 to 10,000 pages/8 hours, which is about 10 to 20 times faster than recording images on an optical disc by directly reading the original 10 with a scanner). This allows you to return the manuscript in a short period of time even if you take it with you. Since images on microfilm can be viewed directly, it is only necessary to input search information after the image is taken, but images recorded on optical discs cannot be viewed directly, so search information must be input at the same time as the images are recorded. Furthermore, microfilm has excellent legal evidence and long-term preservation.

For this reason, it is better to create a microfilm file and then convert only the necessary images to optical disk files, rather than directly reading the image of the original with a scanner and creating an optical disk file. The examples use the kits described below.

The microfilm 16 is loaded into a kit 26 according to its type, and installed into a microfilm reader 28. The microfilm reader 28 is equipped with a screen 30, and the image of the microfilm 16 is displayed on the screen 30.
projected on. Frame feeding of the microfilm 16 is performed in response to input signals from the keyboard 34, and frame addresses and the like are displayed on the CRT display 36. The operator views the memo while viewing the image projected on the screen 30 or without looking at the image, and inputs recording instruction information (for example, search information and reading information) for the image to be converted into an optical disk file.

This recording instruction information is displayed on the CRT display 36 and checked for errors. If there is an error, the error is corrected and then recorded on the floppy disk 38.

On the other hand, independently of the above steps, the conversion of microfilm files into optical disk files is performed automatically and continuously. That is, after the processing by the microfilm reader 28 is completed, the kit 26 and the floppy disk 38 are loaded into the microfilm scanner 40 and the file controller 41, respectively. The image of the microfilm 16 loaded in the kit 26 is displayed on the screen 4.
It is projected on four sides, read by the line sensor 42, binarized, and sent to the optical disk recording device 5 via the wiring 50.
The data is supplied to the file controller 41 of No. 2. The recording instruction information recorded on the floppy disk 38 is read by the file controller 41 and supplied to the microfilm scanner 40 via the wiring 50, and the microfilm scanner 40 feeds the microfilm 16 frame by frame according to this recording instruction information. The digital image data from the microfilm scanner 40 and the search information from the floppy disk 38 for performing the projection, binarization, etc. are processed by the file controller 41 and stored on the optical disk 5.
4 is recorded. Further, this search information is recorded on a recording medium other than the optical disk, such as the floppy disk 55, and is used for high-speed search of optical disk files. The recording instruction information and digital image data are each recorded on a CRT.
Operation signals such as starting and stopping the 0 work displayed and monitored on the display 56 are inputted via the keyboard 58 and supplied to the file controller 41 .

Since the microfilm reader 28 is inexpensive, it is distributed and provided in a plurality of companies, for example, and the optical disk recording device 52 is expensive, so it is provided and used at a central location.

Next, according to FIG.
will be explained in detail.

Roll microfilm 1 wound on supply reel 60
8 is pulled out and wound onto a take-up reel 62.

The middle part of the rolled microfilm 18 is held between the pressure bonding glass mechanism 64 and the screen 3
The image projected onto the line sensor 42 and the image projected onto the line sensor 42 are not distorted. The light from the light source 66 is irradiated onto the roll microfilm 18 through the condenser lens 68, transmitted through the roll microfilm 18, and when the mirror 92 is parallel to the optical axis, passes through the imaging lens 70 to the screen 44 and the roll microfilm 18. Eighteen images are projected.

Supply reel 60. The handle 62 is rotated by a drive signal from a drive circuit 72 being supplied to a motor (not shown). The rotation of the winding wheel 62 is detected by a pulse generator (not shown), and one pulse is output from the pulse generator every time the winding wheel 62 rotates by a certain minute angle.

As shown in FIG.
A page blip mark 122 and a file blip mark 124 indicating the delimitation of blocks of related frames are exposed correspondingly. The address of frame 120 can be detected by sequentially counting page blip marks 122 and file blip marks 124.

The page blip mark 122 and file blip mark 124 shown in FIG. 3 are detected by two blip mark sensors (optical sensors) 76 shown in FIG.

Signals from the pulse generator and blip mark sensor 76 are input to the input port 80 of the microcomputer 7B.
output port 8 of the microcomputer 78.
2 supplies the control signal for the motor to the drive circuit 72. Microcomputer 78 has CPU86, ROM8
B. Equipped with RAM90, CPU86 is ROM8
Processing such as input/output is performed according to the program stored in 8. The RAM 90 is used for temporary storage of recording instruction information and for working purposes.

Image projection onto the line sensor 42 is performed by rotating the mirror 92 around the fulcrum S so that the mirror 92 forms an angle of 45° with the optical axis.
4 onto the line sensor 42. The line sensor 42 is moved in the sub-scanning direction by a sub-scanning mechanism 98 which is moved horizontally on the projection plane by a motor 96. Also,
An automatic exposure sensor 100 is disposed toward the optical path of the projection light, and the amount of light transmitted through the film is detected and supplied to the input port 80 via the A/D converter 102. The signal from the automatic exposure sensor 100 is used to adjust a light amount diaphragm mechanism (not shown) or adjust the lamp voltage to change the amount of light.

The line sensor 42 is main-scanned by a transfer pulse from the main-scanning/reading circuit 104, and a charge proportional to the amount of light received by the element of the line sensor 42 is transferred to the main-scanning/reading circuit 104.
4, which is converted into a voltage and supplied to the A/D converter 106. The signal converted into a digital value by the A/D converter 106 is supplied to the binarization circuit 10B, where it is compared with a threshold value (binarization level) from the microcomputer 78A and converted into a value of 1 or 0. , are sequentially supplied to the line buffer 110 one bit at a time. When performing resolution switching, when two lines of data are supplied to the line buffer 110, this is transferred to the resolution switching circuit 112.
The resolution is switched from 16 dots/square to 8 dots/square by a switching signal from the microcomputer.

The disulfurized data is supplied to the file controller 41 via the interface 114.

Also, the interface 11 is used to exchange control information between the file controller 41 and the microcomputer 7.
8.

The microfilm scanner 40 operates based on control commands from the file controller 41, and the control commands are supplied from the file controller 41 via the interface 118.

Next, the first pixel block group of the line sensor 42, the second pixel block group
A routine for determining the binarization level using the pixel block group and the third pixel group will be described. First, the pixels of the line sensor are classified as follows.

As shown in FIG. 4(1), the line sensor 42
, L) or amorphous silicon, and six pixels are arranged in series. To explain the −C2 tree embodiment, line sensor 421! It is assumed that the pixel block is composed of n pixel blocks, each of which is a plurality of adjacent pixels (for example, 47 pixels?). In addition,
Although n may be any number, in the following description, it is assumed that n is an even number. When each of the pixel blocks of this line sensor is numbered 1, 2, 3, 4, ... n from one end to the other, the numbers 1.3, ... n-1, that is, odd-numbered pixels The block group is used as the first pixel block group, numbered 2.4
,...n/2, that is, the even-numbered pixel block group below the center of the figure is used as the second pixel block group, and the numbers are (n/2) + 2, (n/2) -←4, .・・・
n, that is, an even-numbered pixel block group above the center of the figure is used as the third pixel block group.

In addition, it passes through the diagonal direction of the photometric object of a specific size (for example, A4 or B5) shown in FIG. 4 (2) and the midpoint of the short side a and the center of the long side To enable scanning in a linear direction parallel to the diagonal, a transfer pulse is generated to extract signals from the pixel block every time sub-scanning is performed over a predetermined path M (for example, 1/32nd).

Determination of the binarization level, which will be explained below, is performed before the reading scan. In FIG. 5, in step 140, the pixel block number l determined as shown in FIG.
In the next step 142, the operator projects the frames to be stored onto the screen 44.In the next step 144, the operator sets the reading size and 1 frame as recording instruction information.
After determining the number of pixel blocks to be used by the line sensor according to the partial reading range of the image (Fig. 5 describes an example of using all pixel blocks n shown in Fig. 4 (1)), the mirror 92 is rotated to irradiate the transmitted light from the microfilm in the direction of the line sensor. In the next step 146, the sub-scanning mechanism 98 is driven to start sub-scanning.

In the next step 148, it is determined whether the pixel block number i exceeds the number n of pixel blocks used, and if the pixel block number l does not exceed the number n of pixel blocks used, in step 150 the pixel block number l is Determine whether the number is odd or not.

If the pixel block number l is determined to be an odd number in step 150, a transfer pulse is supplied in step 152 to transfer and store the information of the first pixel block, and then the pixel block number i is incremented in step 154. do.

On the other hand, when it is determined in step 150 that the pixel block number l is an even number, it is determined in step 156 whether the pixel block number l has become 1/2 or less of the number n of used pixel blocks.

When it is determined that the pixel block number i has become less than or equal to n/2, in step 158, the information of the i10n/2th pixel block is transferred and read, and this information is stored in the memory. On the other hand, pixel block number i
If it is determined that the pixel block exceeds n/2, the information of the i-n/2th pixel block is transferred and read in step 160, and this information is stored in the memory, and then the pixel block number l is set in step 154. Increment.

As a result of the control described above, as shown in FIG. 4 (2), the first pixel block group measures light in one direction of the diagonal line, and the second pixel block group measures light in the direction of a straight line parallel to the diagonal line I. is photometered, and the third pixel block group is photometered in the direction of straight line {circle around (2)} parallel to diagonal line I. While the sub-scanning is deviated by a predetermined path as described above, main scanning is performed alternately by the first pixel block group and the second pixel block group or by the first pixel block group and the third pixel block group. Therefore, the photometering sections on the microfilm are made so that they do not overlap on a straight line along the main scanning direction and on each straight line along the sub-scanning direction (the entire screen can be uniformly metered without having to measure the same spot multiple times). Further, the data measured by photometry in the first to third pixel block groups is approximately equivalent to one line sensor.

Note that if the size of the frame of the microfilm is other than the specific size (for example, A3, B4), the tiI area divided into the specific size is photometered by the first to third pixel block groups (the fourth Figure (2)), therefore, if the microfilm frame size is other than the specified size,
Since more information is read than in the case of a specific size, each specific size of information is stored in multiple memories.

When it is determined in step 148 that the pixel block number i exceeds the number n of used pixel blocks, it is determined that the photometry of a frame of a specific size has been completed, and step 16
In step 2, the binarization level is calculated, for example, by averaging the information stored in the memory. Then, in step 164, the line sensor 42 is moved at high speed to be located at the initial position for microfilm reading scanning.In step 166, the main scanning is performed by sequentially extracting signals from each pixel of the line sensor. The photometric data is stored in the memory, and in the next step 168 it is determined whether or not the reading scanning process has been completed. When it is determined that the reading scanning process has been completed, this routine is terminated.

In addition, above, an example was explained in which the line sensor is returned to the reading scan start position after performing a preliminary scan to determine the binarization level, and then the reading scan is performed. A preliminary scan may be performed when the line sensor is moved and then returned to the scan start position.

Furthermore, in the above example, the sub-scanning is performed by moving the line sensor, but the sub-scanning may also be performed by moving the photometric object such as a microfilm. Although the example of determining the binarization level of information recorded on a document such as paper has been described, the present invention can also be applied to the case of determining the binarization level of information recorded on a document such as paper.

In the above, an example was explained in which three areas of the object to be photometered are photometered approximately diagonally; photometry), only the peripheral area of the object to be photometered (for example, when the text information is biased toward the periphery), photometry can be performed according to the bias state of the text information, or randomly.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram showing a file conversion system to which the present invention can be applied, Figure 2 is a configuration diagram showing details of the microfilm scanner shown in Figure 1, and Figure 3 is a frame and blip mark of roll microfilm. Figure 4 (1) is a diagram showing the arrangement of pixel blocks of the line sensor, Figure 4 (2) is a diagram showing the scanning direction by the line sensor, and Figure 5 is a diagram showing the binarization. 2 is a flow diagram illustrating a routine for determining levels. 40...Microfilm scanner 41...File controller 42...Line sensor 52...Magnetic disk recording device 54...Optical disk 98...Sub-scanning mechanism

Claims (3)

[Claims] (1) When photometrically measuring a photometric object by relatively moving a line sensor in which a plurality of pixels are arranged in series and the photometric object and performing sub-scanning, a signal is extracted from the line sensor and main scanning is performed. A photometry method comprising dividing the plurality of pixels into a plurality of pixel blocks each consisting of a plurality of adjacent pixels, and intermittently extracting a signal from each of the plurality of pixel blocks for photometry. (2) Divide the plurality of pixel blocks into a plurality of pixel block groups, sequentially select one pixel block group from the plurality of pixel block groups, and extract signals from the pixel blocks belonging to the selected pixel block group. A photometry method according to claim (1), in which the photometry is performed by taking out the photometer. (3) The plurality of pixel blocks are divided into a first pixel block group arranged at one pixel block interval and a pixel block group not included in the first pixel block group in a direction perpendicular to the pixel arrangement direction. The signal is extracted from one pixel block belonging to the first pixel block group and the signal from one pixel block belonging to the second pixel block group is divided into a second pixel block group and a third pixel block group. After alternately extracting signals from the pixel blocks, the first
Claim (1): photometry is performed by alternately extracting a signal from one pixel block belonging to the pixel block group and extracting a signal from one pixel block belonging to the third pixel block group. Photometry method described in section.