JPH0766987A - Original reader - Google Patents

Abstract

PURPOSE:To obtain the original reader in which the processing for adjusting a luminance level and a white balance is executed with high accuracy in a short time. CONSTITUTION:When scanning is started, a matrix circuit 11 extracts part of R, G, B signals from A/D converters 8, 9, 10 before conversion into Y, C signals and stores the part of the signal to a memory (RAM) of a microcomputer 16. When scanning is stopped, before the Y, C signals are read from Y, C memories 12, 13, the microcomputer 16 executes the arithmetic operation processing for adjusting a luminance level and a white balance based on the stored R, G, B signals and a gain and a phase of the Y, C signals are set for an output processing circuit 14 so as to obtain optimum luminance level and white balance based on the result of arithmetic operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographic film player for displaying a photographed image of a developed photographic film on a picture tube screen, and a document reading device suitable for use as an input device of a personal computer. is there.

[0002]

2. Description of the Related Art Conventionally, an original reading device used as, for example, a photographic film player irradiates a positive or negative developed photographic film as an original with light from a light source, and transmits light from the photographic film to an image pickup means. When the light is incident, the captured image is read. Then, the red (R), green (G), and blue (B) three primary color signals (hereinafter, referred to as “R, G, B signals”) obtained from the image capturing means are obtained as luminance (Y) and color difference ( RY, BY signals (hereinafter referred to as "Y, C signals") are converted and output.

FIG. 8 shows a specific example of the structure, 1 is a linear light source corresponding to the reading width of the film, 2 and 3 and 4 are film feeding motors and rollers 5 which are rotationally driven by the motors. Each of the R, G, and B lights is incident on the lens 6 (in this case, the R, G, B lights separated into the three primary colors) are photoelectrically converted to output R, G, B signals. CCD (charge) with a 3-line structure having lines
coupled device). Therefore, when the film F is irradiated with the light from the linear light source 1 at the start of scanning, the light transmitted through the film F is condensed by the lens 6 and is incident on the CCD 5, and R for one line of the film F,
It will be output as G and B signals. Then, when the film F is fed (sub-scanned) by the motor and the rollers 2, 3 and 4 for one frame (one frame) in this state, the scanning is stopped.

Reference numeral 7 is an analog signal processing circuit for performing CDS processing for performing correlated double sampling, amplification processing, black level clamp processing, etc. on the R, G, B signals from the CCD 5 obtained by such scanning, 8, 9 10 is an A / D converter for converting the R, G, B signals from the analog signal processing circuit 7 into digital signals, 11 is an A / D converter 8,
A matrix circuit for converting R, G, B signals in digital signal form from 9 and 10 into Y and C signals, and 12 and 13 luminance and color difference for respectively storing Y and C signals for one frame from the matrix circuit 11. Memory (hereinafter, "Y, C memory"
), 14 is an output processing circuit for subjecting the Y and C signals read from the Y and C memories 12 and 13 to output processing suitable for picture tube display in this case.

In such an apparatus, in order to adjust its brightness level and white balance, Y, C
Before reading the Y and C signals stored in the memories 12 and 13 and outputting them from the output processing circuit 14, the Y and C memory 1
A part of the Y and C signals are read out from Nos. 2 and 13 and inversely converted into the original R, G and B signals by the inverse conversion matrix 15 and output to the microcomputer (hereinafter referred to as “microcomputer”) 16. Then, R obtained by inverse conversion by the microcomputer 16,
Brightness level based on G and B signals, arithmetic processing for white balance adjustment (for example, in the case of a brightness level, the average brightness of a person and the background is obtained, and it is determined whether the light is backlight or forward light, and the appropriate value in the memory of the microcomputer 16 Level and comparison processing), and the gain and phase of the Y and C signals in the output processing circuit 14 are set based on the calculation result.
The Y and C signals were read out from the output terminal 13 and output from the output processing circuit 14.

[0006]

However, in the apparatus having such a conventional structure, a part of the Y and C signals stored in the Y and C memories is once converted back to the R, G and B signals and then the brightness level is changed. Since the process for adjusting the white balance has to be performed, the process takes time.
If the brightness level and white balance adjustment calculation processing is performed on the Y and C signals as they are without performing the inverse conversion, the accuracy of the brightness level and white balance adjustment will be significantly reduced. Further, since the digital conversion is performed twice from the R, G, B signals to the Y, C signals and again to the R, G, B signals, the data of the inversely converted R, G, B signals is obtained. The accuracy of is also reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an original reading apparatus capable of accurately performing processing for adjusting a brightness level and white balance in a short time. It is what

[0008]

In order to achieve the above object, according to the present invention, a document is read by an image pickup means (in this case, a CCD as a one-dimensional image pickup element), and red, green, and blue from the image pickup means are read. In an original reading apparatus which converts the R, G, B signals into Y and C signals and outputs them, a part of the R, G, B signals before conversion into Y and C signals is taken out and stored,
Based on the stored R, G, B signals, output Y,
The circuit means is provided for performing both or either of the brightness level of the C signal and the white balance adjustment.

[0009]

According to this structure, the brightness level and white balance of the Y and C signals to be output are adjusted based on the R, G and B signals before being converted into the Y and C signals. The accuracy of adjustment will be improved. Also,
Since the process of inversely converting the Y and C signals into the R, G and B signals is not necessary, the time required for this process is shortened.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same parts as those of the related art are designated by the same reference numerals and the description thereof will be omitted. First, FIG. 1 shows a first embodiment. When the scan is started, the A / D converter 8 before conversion into Y and C signals by the matrix circuit 11,
A part of the R, G, B signals from 9, 10 is taken out by thinning out by sampling and stored in the memory (RAM) of the microcomputer 16. When the scan is stopped, the Y and C memories 12, 13 are
Before reading the Y and C signals from the
The microcomputer 16 performs a brightness level / white balance adjustment calculation process based on the B signal, and the Y and C signal gains in the output processing circuit 14 so that the optimum brightness level and white balance are obtained based on the calculation result. , The phase is set. By doing so, the Y and C signals read from the Y and C memories 12 and 13 after the scan is stopped are automatically adjusted by the output processing circuit 14 to the optimum brightness level and white balance, and then output. .

Here, sampling for extracting a part of the R, G, B signals is performed by controlling writing to the memory based on a timing signal from a timing signal generation circuit (not shown). It has become. For example, when the R, G, B signals for one pixel on the film F are sequentially sampled based on the timing signal as indicated by circles in FIG. 5, the R, G, 1/64 decimated, Since the B signal is taken out and stored in the memory (RAM) of the microcomputer 16, the contribution rate (sampling rate) of the R, G, B signals for one frame to the arithmetic processing becomes 1.56%. . The timing signal generation circuit also generates and supplies timing signals for photoelectric conversion processing, analog signal processing, A / D conversion processing, signal conversion processing, writing / reading processing, output processing, and the like. In addition, the microcomputer 16
May be a system microcomputer that controls the entire system, or may be dedicated to arithmetic processing.

Next, FIG. 2 shows an A / D obtained during scanning.
A part of the R, G, B signals from the converters 8, 9, 10 is taken out by sampling thinning out, stored in the R, G, B memory 17 separately provided for it, and stored after the scanning is stopped. The microcomputer 16 is made to perform arithmetic processing for brightness level and white balance adjustment based on the R, G and B signals. By doing so, the number of R, G, B signals (the number of sampling data) taken out during scanning can be increased. For example, the memory of the microcomputer 16 is generally 1 in the case of a one-chip microcomputer.
Since it is about k bytes, it is necessary to reduce the sampling points of the R, G, B signals obtained during scanning, but if a dedicated memory 17 of about 20 kbytes is provided, the sampling points can be increased at least 20 times. Therefore, it is possible to perform highly accurate calculation processing for brightness level and white balance adjustment.

Further, FIG. 3 shows the R, G, B signals for the calculation processing for adjusting the brightness level and the white balance as described above, and the margins of the Y and C memories (larger than the memory capacity of the one-chip microcomputer). The third embodiment will be described below. This is because the capacity of a commercially available DRAM, SRAM, or the like is fixed, and a memory having a capacity larger than the Y and C signals for one frame is used as the Y and C memory. In this case, one memory is used. The Y and C memory areas 12A and 13A and the R, G and B memory areas 17A are used separately. This way, at the start of the scan,
A part of the R, G, B signals from the A / D converters 8, 9, 10 is taken out by thinning out by sampling and stored in the R, G, B memory area 17A of the memory, and the scan is stopped. And its R, G, B memory area 17A
Based on the R, G, B signals read from the microcomputer 1
At 6, the brightness level and white balance adjustment calculation processing is performed. As a result, a separate dedicated memory 17
Therefore, it is possible to perform highly accurate calculation processing for brightness level and white balance adjustment without providing the above.

Next, FIG. 4 shows such first, second, and third types.
In the flowchart showing the control operation for adjusting the brightness level and the white balance of the microcomputer 16 in the embodiment of the above, first, the scanning of the film F is started in step # 5, and the CCD 5 performs R for one line of the film F,
When the G and B signals are obtained, the process proceeds to step # 10. Then, in step # 10, only the R, G, and B signals to be sampled within that line are taken out, and the next step # 15
The memory of the microcomputer 16 or the R, G, B memory 17,
Alternatively, it is stored in the R, G, B memory area 17A. Then, in step # 20, it is determined whether or not it is within the image range captured in one frame of the film F, and the scan is continued until it is determined that the image is not within the image range, and the scan is performed for one line. Steps # 10, # 15, and # 20 are repeated each time the R, G, and B signals are obtained. At this time, the number of lines is managed also in the sub-scanning direction to appropriately perform thinning.

If it is determined in step # 20 that the image is not within the image range, the process proceeds to step # 25 to stop scanning, and in step # 30, the memory of the microcomputer 16 or the R, G, B memory 17, or R, G, B memory area 1
Based on the R, G, and B signals stored in 7A, the brightness level and white balance adjustment calculation processing is performed. Then, in step # 35, the gain and phase of the Y and C signals in the output processing circuit 14 are set based on the calculation result,
The control flow ends. As a result, the Y and C signals for one frame stored during the subsequent scanning are read out from the Y and C memories 12 and 13 to output the output processing circuit 1.
4, the output processing circuit 14 adjusts the luminance level and white balance for the Y and C signals.

In the first, second and third embodiments, the R, G, B signals for one pixel on the film are treated as one sampling data in the memory of the microcomputer 16 or the R, G, B memory 17, or The data is stored in the R, G, B memory area 17A, but the average of R, G, B signals for several pixels over several lines is used as one sampling data in the memory of the microcomputer 16 or R, G. , B memory 17,
Alternatively, it may be stored in the R, G, B memory area 17A. For example, if the average of the R, G, and B signals for 4 × 2 = 8 pixels across 4 lines of 4 pixels is stored as one sampling data, as indicated by the ellipse mark in FIG. The contribution rate (sampling rate) of the R, G, B signals for one frame to the arithmetic processing is increased from 1.56% in the case of FIG. 5 to 12.5% even if the number of samples is the same.
The brightness level and the accuracy of white balance adjustment are improved accordingly. However, in this case, 8 across 2 lines
A buffer memory for delaying the R, G, B signals from the A / D converters 8, 9, 10 by one line is necessary to obtain the average of the R, G, B signals for the pixels. 1 line delayed signal from R and G of current line
After being averaged for 8 pixels by the microcomputer 16 or the hard logic from the B signal, it is stored.

Further, in the first, second and third embodiments, the brightness level and the white balance adjustment are Y and C memories 12 and 1, respectively.
Although the output conditions of the Y and C signals read from No. 3 are changed, the conditions before being stored in the Y and C memories 12 and 13 are changed by, for example, prescan and main scan. May be. By doing so, the brightness level and white balance adjustment can be performed at the stage of the R, G, and B signals before conversion into the Y and C signals, so the S / N ratio and color reproducibility are improved, and the image quality is improved. Can be improved. FIG. 7 is a flowchart showing the control operation of the microcomputer 16 in such a case. First, in step # 50, pre-scanning of the film F is started, and CC
When the R, G, B signals for one line of the film F are obtained by D5, the process proceeds to step # 55. Then, in step # 55, the R, G, and
Only the B signal is taken out, and in the next step # 60, the memory of the microcomputer 16 or the R, G, B memory 17, or R,
The data is stored in the G and B memory areas 17A, and thinning is performed by managing the number of lines in the sub-scanning direction. Then, in step # 65, it is determined whether or not the scan for the area required for the adjustment processing of the brightness level and the white balance has been completed within the image range photographed on one frame of the film F. Here, the pre-scan is continued until it is determined that the area scan is completed,
Each time R, G, B signals for a line are obtained, step #
55, # 60, and # 65 will be repeated.

When it is determined in step # 65 that the scanning of the required area has been completed, the process proceeds to step # 70 to stop the prescan, and in step # 75, the memory of the microcomputer 16 or the R, G, B memory is stopped. 17 or brightness, white balance adjustment calculation processing based on the R, G, B signals stored in the R, G, B memory area 17A. Then, in step # 80, the lens diaphragm or ND (neutral) is calculated based on the calculation result.
density) or the brightness of the light source 1 is set, and the gains of the R, G and B signals are set in the analog signal processing circuit 7 or the like in step # 85. Then, the main scan is started in step # 90, the Y and C signals obtained thereby are stored in the Y and C memories, and when the scanning of one frame of the film F is completed, the main scan is stopped in step # 100. And then step # 105
Then, the Y and C signals are read from the Y and C memories 12 and 13 and output from the output processing circuit 14, and the control flow is ended. In such a control flow, the memory of the microcomputer 16 or the separate R, G, B memory 17, or the margins of the Y, C memories 12, 13 are stored for storing the R, G, B signals during the prescan. I am trying to use
It is also possible to use the Y and C memories 12 and 13 themselves.

[0019]

As described above, according to the present invention, in the document reading apparatus for reading the document by the image pickup means, converting the R, G and B signals from the image pickup means into the Y and C signals and outputting the signals. Since a part of the R, G, B signals before being converted into the Y, C signals is used to adjust the brightness level and white balance of the Y, C signals, the process for the adjustment is short. You will be able to do it accurately in time.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a flowchart showing the control operation of the microcomputer.

FIG. 5 is a diagram showing an example of the sampling.

FIG. 6 is a diagram showing another example of the sampling.

FIG. 7 is a flowchart showing another control operation example of the microcomputer.

FIG. 8 is a diagram showing a conventional configuration example.

[Explanation of Codes] 5 CCD 7 Analog signal processing circuit 8, 9, 10 A / D converter 11 Matrix circuit 12, 13 Y, C memory 14 Output processing circuit 17 R, G, B memory

Claims (1)

[Claims] 1. A document reading apparatus for reading a document by an image pickup means, converting red, green, and blue primary color signals from the image pickup means into luminance and color difference signals and outputting the luminance and color difference signals. A circuit means is provided for extracting and storing a part of the three primary color signals of, and outputting the luminance, the luminance level of the color difference signal and / or the white balance adjustment based on the stored three primary color signals. Document reading device.