JP3655655B2 - Image input device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an apparatus for inputting an image by a linear sensor, such as a film scanner.
[0002]
[Prior art]
Conventionally, an apparatus for detecting pixel information on a screen by moving a linear sensor along the screen is disclosed in, for example, Japanese Patent Laid-Open No. 5-167774. The apparatus scans the linear sensor in the sub-scanning direction (vertical direction) of the screen and detects the first pixel information, and then shifts the linear sensor by a predetermined amount in the main scanning direction (horizontal direction) of the screen, The second pixel information is detected by scanning again in the sub-scanning direction. By combining the first and second pixel information, the sub-scan is performed twice as compared with the case where the sub-scan is performed only once. A resolution image is obtained.
[0003]
[Problems to be solved by the invention]
Thus, a device that shifts the linear sensor by a predetermined amount in the main scanning direction and performs sub-scanning a plurality of times not only has a mechanically complicated configuration, but also the accuracy of the obtained image is sufficient depending on the accuracy of the shift amount. There is also a problem that the control for moving the linear sensor becomes complicated.
[0004]
An object of the present invention is to provide an image input device capable of obtaining a highly accurate image with a simple configuration and control.
[0005]
[Means for Solving the Problems]
An image input device according to the present invention is a device for inputting pixel information of a screen having a rectangle, and extends in a direction inclined with respect to an edge extending in the horizontal direction of the screen, and a linear sensor capable of detecting pixel information; Each time the linear sensor detects pixel information , the linear sensor is linearly moved along the screen in a direction orthogonal to the above-described inclination direction, and only at a pitch corresponding to the distance between the pixels along the width direction of the linear sensor. A sub-scanning mechanism for moving and means for reading out a pixel signal corresponding to the screen from the linear sensor are provided.
[0006]
【Example】
The present invention will be described below with reference to illustrated embodiments.
FIG. 1 is a block diagram showing a schematic configuration of an image input apparatus according to an embodiment of the present invention.
[0007]
The linear sensor 11 includes a large number of photodiodes arranged in a row and a transfer unit that transfers signal charges (pixel signals) accumulated in the photodiodes by photoelectric conversion. The linear sensor 11 is driven by the sub-scanning mechanism 12 and is not illustrated. It can move along the screen. The linear sensor 11 is driven by a pulse signal output from the drive circuit 13 and outputs a pixel signal. The pixel signal is amplified by an amplifier 14, high-frequency noise is removed by a low-pass filter 15, and then converted into a digital signal by an A / D converter 16. This digital pixel signal is stored in the memory 18 under the control of the memory control circuit 17.
[0008]
The pixel signal stored in the memory 18 is subjected to interpolation processing by the interpolation processing circuit 21 in order to increase the resolution of the reproduced image, and then stored in the memory 18 again. The interpolated pixel signal is read from the memory 18 and converted into an analog signal by the D / A converter 22 under the control of the memory control circuit 17. The analog pixel signal is output to a monitor (display device) after high-frequency noise is removed by the low-pass filter 23. On the other hand, the digital pixel signal read from the memory 18 can be output to a computer or the like as it is.
[0009]
The system control circuit 24 controls the image input device as a whole, operates based on clock pulses output from the clock generator 25, and outputs a predetermined command signal.
[0010]
The sub-scanning mechanism 12 operates based on a command signal from the system control circuit 24, whereby the linear sensor 11 performs sub-scanning on the screen. That is, after detecting pixel information at a predetermined position on the screen, the linear sensor 11 moves by one step, detects image information again, and moves on the screen while repeating such detection operation. The drive circuit 13 operates based on a command signal from the system control circuit 24 and a clock pulse output from the clock generator 25, whereby a pixel signal is output from the linear sensor 11. The memory control circuit 17 operates based on a command signal from the system control circuit 24 and a clock pulse from the clock generator 25, thereby A / D conversion operation of the A / D converter 16, and writing and reading of the memory 18. Operation, D / A conversion operation of the D / A converter 22 is controlled. The interpolation processing circuit 21 also operates based on a command signal from the system control circuit 24.
[0011]
FIG. 2 is a diagram showing sub-scanning of the linear sensor 11 in the first embodiment, and FIG. 3 is a flowchart showing a pixel signal reading operation in the first embodiment. With reference to these drawings, an operation for detecting pixel information from the screen F will be described.
[0012]
The screen F has a rectangle that is longer in the horizontal direction than in the vertical direction. The linear sensor 11 extends in a direction inclined by 45 degrees with respect to the edge P1 extending in the horizontal direction of the screen F. The linear sensor 11 is linearly moved in the vertical direction of the screen F by the sub-scanning mechanism 12 (FIG. 1). That is, the sub-scanning direction of the linear sensor 11 is parallel to the vertical direction of the screen F. The linear sensor 11 has a length sufficient to detect the pixels of the screen F by sub-scanning, that is, about 2 ^1/2 times the edge P1.
[0013]
The linear sensor 11 moves by a predetermined step width each time pixel information is detected. This step width is 2 ^1/2 times the distance D (pixel pitch) between the pixels along the width direction of the linear sensor 11. When the linear sensor 11 is moved i times by the step width, all pixels in a predetermined row aligned in the vertical direction of the screen F are detected, and when the linear sensor 11 is moved j times by the step width, the predetermined pixels aligned in the horizontal direction of the screen F are detected. All pixels in the row are detected. Further, all the pixels on the screen F are detected by moving the linear sensor 11 by the step width (n = i + j−1) times. This (i + j−1) adds the number j of pixels arranged along the horizontal edge P1 of the screen F and the number i of pixels arranged along the vertical edge P2 of the screen F. This is obtained by subtracting by the amount of the pixel S1 at the right corner of the screen, which is considered redundantly in counting the numbers j and i. Note that the number of photodiodes of the linear sensor 11 is (2j−1).
[0014]
In step 101, the parameter k is set to 1, and in step 102, the linear sensor 11 is set to the initial position. That is, at time t = t ₁ , as shown in FIG. 2, the linear sensor 11 has the first photodiode (located at the left end and indicated by reference numeral (1)) corresponding to the upper left pixel S2 of the screen F. Fixed in position.
[0015]
In step 103, the pixel signal is read from the linear sensor 11. The pixel signals read at this time are all pixel signals detected by the linear sensor 11. In step 104, it is determined whether or not the parameter k is smaller than i. When step 104 is executed for the first time, the parameter k is smaller than i, so step 105 is executed next. The pixel signals read in step 103 are all the pixel signals detected by the linear sensor 11, but as can be understood from FIG. 2, the pixel signals corresponding to the pixels on the screen F are part of the linear sensor 11. This is a pixel signal detected by the photodiode. In step 105, pixel signals detected by the first to (2k−1) th photodiodes of the linear sensor 11 are stored in a predetermined area of the memory 18. That is, when the parameter k is 1 (time t = t ₁ ), only the first pixel signal of the linear sensor 11 is stored in the memory 18.
[0016]
In step 106, it is determined whether or not the parameter k has reached the number of steps n (= i + j−1) when the linear sensor 11 detects all pixel information on the screen F. At first, since the number of steps n has not yet been reached, the parameter k is incremented by 1 in step 107, the linear sensor 11 is sub-scanned by 1 step in step 108, and the process returns to step 103. Steps 104 and 105 are executed again. When the linear sensor 11 moves by one step, as can be understood from FIG. 2, the number of pixels detected on the screen F, that is, the number of pixel signals to be stored in the memory 18 in step 105 increases by two. To do. Accordingly, in step 105, pixel signals corresponding to the first to (2k−1) th photodiodes of the linear sensor 11 are stored in the memory 18.
[0017]
When the parameter k becomes equal to i by execution of step 107 (time t = t _i ), the linear sensor 11 is sub-scanned by one step in step 108, and all pixel signals are read from the linear sensor 11 in step 103. Thereafter, in step 111, it is determined whether or not the parameter k is larger than j. When step 111 is executed for the first time, the parameter k is equal to or less than j, so step 112 is executed, and the pixel signals corresponding to the (k−i + 1) th to (2k−1) th photodiodes of the linear sensor 11. Is stored in a predetermined area of the memory 18. That is, when the parameter k is a value from i to j (time t = t _{i to} t _j ), the first pixel signal stored in the memory 18 is the position where the parameter k is subtracted i and 1 is added. This corresponds to the photodiode (pixel S3). Thus, in the time t = t _{i to} t _j , the loop composed of the steps 103, 104, 111, 112, 106, 107, 108 is repeatedly executed.
[0018]
When the parameter k becomes larger than j (time t> t _j ), the process proceeds from step 111 to step 113, and pixel signals corresponding to the (k−i + 1) th to (2j−1) th photodiodes of the linear sensor 11. Is stored in a predetermined area of the memory 18. That is, when the parameter k is larger than j, the top pixel signal stored in the memory 18 corresponds to the (k−i + 1) th pixel as in step 112, but the last pixel signal stored in the memory 18 The pixel signal is a pixel signal obtained by the rearmost photodiode (right end) of the linear sensor 11.
[0019]
After the time t = t _{j, a} loop composed of steps 103, 104, 111, 113, 106, 107, 108 is repeatedly executed. During this time, in step 106, the parameter k is the number of steps n (= i + j−1). If it is determined that this value has been reached, this routine ends.
[0020]
When the routine of FIG. 3 is completed, the pixel signals stored in the memory 18 are arranged on the screen F along a line L inclined by 45 degrees with respect to the horizontal line as shown by a circle in FIG. Yes. There is no pixel signal between the adjacent pixels in the odd-numbered row H1 (for example, the symbols X1 and X2) and between the adjacent pixels in the even-numbered row H2 (for example, the symbols X3 and X4). In this embodiment, a pixel signal (for example, Y1) located between two pixel signals (for example, X1 and X2) input from the linear sensor 11 is obtained by taking an average value of the two pixel signals, and the memory 18. As a result, the number of pixels on the screen F is increased by a factor of two compared with that detected by the linear sensor 11, and the resolution of the reproduced image is increased.
[0021]
As described above, according to the first embodiment, it is possible to obtain information on pixels that are densely arranged on the screen F by only performing sub-scanning once without shifting the linear sensor 11 in the main scanning direction. . That is, according to the present embodiment, a highly accurate image can be obtained with a mechanically simple configuration, and the cost of the image input apparatus can be reduced. Further, according to the present embodiment, since it is not necessary to shift the linear sensor 11 in the main scanning direction, the control of the image information detection operation is simple.
[0022]
Next, a second embodiment will be described. Compared with the first embodiment, the second embodiment has the same block diagram of the apparatus, but the sub-scanning direction of the linear sensor 11 and the storage operation of the pixel signal in the memory are different.
[0023]
FIG. 5 is a diagram showing sub-scanning of the linear sensor 11 in the second embodiment, and FIG. 6 is a flowchart showing a pixel signal reading operation in the second embodiment. With reference to these drawings, an operation for detecting pixel information from the screen F will be described.
[0024]
As in the first embodiment, the screen F has a rectangular shape that is longer in the horizontal direction than in the vertical direction, and the linear sensor 11 extends in a direction inclined by 45 degrees with respect to the edge P1 extending in the horizontal direction. ing. The sub-scanning direction of the linear sensor 11 is the horizontal direction of the screen F.
[0025]
The linear sensor 11 has a length that is approximately 2 ^1/2 times the edge P2 extending in the vertical direction of the screen F. When the linear sensor 11 is moved i times in the horizontal direction by a predetermined step width, all pixels in a predetermined row arranged in the vertical direction of the screen F are detected. All pixels in a predetermined row arranged in the horizontal direction are detected. Further, all the pixels on the screen F are detected by moving the linear sensor 11 by the step width (n = i + j−1) times. Note that the number of photodiodes of the linear sensor 11 is (2i-1).
[0026]
The processing in steps 201 and 202 is the same as the processing in steps 101 and 102 in FIG. 3, and at time t = t ₁ , as shown in FIG. 5, the linear sensor 11 is positioned at the first photodiode (located at the right end). , Indicated by reference numeral (1)) is fixed at a position corresponding to the upper left pixel S2 of the screen F.
[0027]
The processing in steps 203 to 208 is the same as the processing in steps 103 to 108 in FIG.
[0028]
When the parameter k becomes equal to i (time t = t _i ), the process proceeds from step 204 to step 211, where it is determined whether or not the parameter k is larger than j. When the step 211 is executed for the first time, the parameter k is equal to or less than j. Therefore, the process proceeds to the step 212, and the pixel signals corresponding to the first to (2i-1) th photodiodes of the linear sensor 11 are predetermined in the memory 18. It is stored in the area. That is, when the parameter k is a value from i to j (time t = t _{i to} t _j ), all pixel signals output from the linear sensor 11 are stored in the memory 18.
[0029]
When the parameter k becomes larger than j (time t> t _j ), the process proceeds from step 211 to step 213, and pixel signals corresponding to the (k−j + 1) th to (2i−1) th photodiodes of the linear sensor 11. Is stored in a predetermined area of the memory 18. That is, when the parameter k is larger than j, the first pixel signal stored in the memory 18 is the first pixel signal obtained by subtracting 1 from the number k of pixels arranged in the horizontal direction at the upper end of the screen F and the like and adding 1. The last pixel signal corresponding to the pixel S4 and stored in the memory 18 corresponds to the pixel S5 obtained by the photodiode at the left end of the linear sensor 11.
[0030]
After the time t = t _{j, a} loop composed of steps 203, 204, 211, 213, 206, 207, 208 is repeatedly executed. During this time, in step 206, the parameter k is the number of steps n (= i + j−1). If it is determined that this value has been reached, this routine ends.
[0031]
Also in the second embodiment, information on pixels located between the pixels is obtained by interpolation.
[0032]
As described above, according to the second embodiment, in addition to the same effects as those of the first embodiment, the length of the linear sensor 11 is about ^21/2 times the longitudinal edge P2 of the screen F. Since there is only need, the linear sensor 11 may be shorter than the first embodiment.
[0033]
Next, a third embodiment will be described. Compared with the first and second embodiments, the third embodiment has the same block diagram of the apparatus, but the sub-scanning direction of the linear sensor 11 and the operation of storing the pixel signals in the memory are different.
[0034]
FIG. 7 is a diagram showing sub-scanning of the linear sensor 11 in the third embodiment, and FIG. 8 is a flowchart showing a pixel signal reading operation in the third embodiment. With reference to these drawings, an operation for detecting pixel information from the screen F will be described.
[0035]
The screen F has a rectangular shape that is longer in the horizontal direction than in the vertical direction as in the first and second embodiments, and the linear sensor 11 is inclined by 45 degrees with respect to the edge P1 extending in the horizontal direction. It extends to. The sub-scanning direction of the linear sensor 11 is the width direction of the linear sensor 11. That is, the step width of the linear sensor 11 is the same as the distance D between the pixels, unlike the first and second embodiments. Note that the number of photodiodes in the linear sensor 11 is (i + j−1).
[0036]
In step 301, the parameter k is set to 1. In step 302 (time t = t ₁ ), the i-th photodiode of the linear sensor 11 corresponds to the upper left pixel S2 of the screen F as shown in FIG. Fixed in position. In step 303, all pixel signals are read from the linear sensor 11. In step 304, it is determined whether or not the parameter k is smaller than i. When step 304 is executed for the first time, the parameter k is smaller than i, so step 305 is executed next.
[0037]
In step 305, pixel signals corresponding to the (i−k + 1) th to (i + k−1) th photodiodes of the linear sensor 11 are stored in a predetermined area of the memory 18. The pixel signals stored in the memory 18 correspond to the pixels located between the pixel S6 and the pixel S7 in FIG. 7, and in the linear sensor 11, (k−1) pieces of pixels are on the left side of the pixel S6. There are photodiodes, and (k−1) photodiodes exist on the right side of the pixel S7. A pixel S8 located at the center between the pixels S6 and S7 corresponds to the i-th pixel of the linear sensor 11. Therefore, the first pixel signal stored in the memory 18 corresponds to the [i− (k−1)] th photodiode of the linear sensor 11, and the last pixel signal stored in the memory 18 is the linear sensor 11. Corresponds to the [i + (k−1)] th photodiode.
[0038]
When the parameter k becomes equal to i (time t = t _i ), the process proceeds from step 304 to step 311 and it is determined whether or not the parameter k is larger than j. When the step 311 is executed for the first time, the parameter k is equal to or less than j. Therefore, the process proceeds to the step 312 and pixel signals corresponding to the (k−i + 1) th to (i + k−1) th photodiodes of the linear sensor 11 It is stored in a predetermined area of the memory 18. When it is time t = t _i after a photodiode which is located on the left side of the pixel S9 in the linear sensor 11 is (k-i) pieces. Therefore, the top pixel signal stored in the memory 18 corresponds to the (k−i + 1) th photodiode of the linear sensor 11. The last pixel signal stored in the memory 18 is the same as before time t = t _i .
[0039]
When the parameter k becomes larger than j (time t> t _j ), the process proceeds from step 311 to step 313, corresponding to the photodiodes from the (k−j + 1) th to the (i + 2j−k−1) th of the linear sensor 11. The pixel signal is stored in a predetermined area of the memory 18. In the linear sensor 11, the last pixel signal stored in the memory 18 corresponds to the pixel S10, and (k−j) photodiodes exist on the right side of the pixel S10. Therefore, the last pixel signal stored in the memory 18 is obtained by subtracting (k−1) from the number (i + j−1) of all photodiodes, and corresponds to the (i + 2j−k−1) th photodiode. . Note that the top pixel signal stored in the memory 18 is the same as the time t = t _{i to} t _j .
[0040]
After the time t = t _{j, a} loop composed of steps 303, 304, 311, 313, 306, 307, 308 is repeatedly executed. During this time, in step 306, the parameter k is the number of steps n (= i + j−1). If it is determined that this value has been reached, this routine ends.
[0041]
Also in the third embodiment, information on pixels located between the pixels is obtained by interpolation.
[0042]
In the above embodiments, the photodiodes of the linear sensor 11 are provided in a sufficient number for detecting all the pixels on the screen F. However, the number may be increased or decreased according to the purpose.
[0043]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain an effect that a highly accurate image can be obtained with a simple configuration and control.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of a still video camera including an image input apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing sub-scanning of the linear sensor in the first embodiment.
FIG. 3 is a flowchart showing a pixel signal reading operation in the first embodiment;
FIG. 4 is a diagram illustrating an interpolation process.
FIG. 5 is a diagram showing sub-scanning of the linear sensor in the second embodiment.
FIG. 6 is a flowchart showing a pixel signal read operation in the second embodiment.
FIG. 7 is a diagram illustrating sub-scanning of the linear sensor in the third embodiment.
FIG. 8 is a flowchart showing a pixel signal read operation in the third embodiment;
[Explanation of symbols]
11 Linear sensor 12 Sub-scanning mechanism

Claims (5)

A device for inputting pixel information of a screen having a rectangle,
A linear sensor extending in a direction inclined with respect to an edge extending in the horizontal direction of the screen and capable of detecting the pixel information;
Each time the linear sensor detects the pixel information, the linear sensor linearly corresponds to the direction perpendicular to the tilt direction along the screen and corresponds to the distance between the pixels along the width direction of the linear sensor. A sub-scanning mechanism that moves only the pitch to be
An image input apparatus comprising: means for reading out a pixel signal corresponding to the screen from the linear sensor.   The image input device according to claim 1, wherein the linear sensor extends in a direction inclined by 45 degrees with respect to an edge of the screen. A device for inputting pixel information of a screen having a rectangle,
A linear sensor extending in a direction inclined by 45 degrees with respect to an edge extending in the horizontal direction of the screen, and capable of detecting the pixel information;
Wherein each of the linear sensor detects the pixel information, the linear sensor only 2 ^1/2 times the pitch corresponding to the distance between pixels along the width direction of the linear sensor, the longitudinal direction along the screen Or a sub-scanning mechanism that moves linearly in the horizontal direction;
An image input apparatus comprising: means for reading out a pixel signal corresponding to the screen from the linear sensor. The image input apparatus according to the pixel information positioned between the pixel corresponding to the pixel signals read by said reading means, to one of the claims 1 or 3, characterized in that it comprises a means for forming by interpolation . The reading means stores, in a storage means, an image signal read from a pixel of the linear sensor that overlaps the screen based on a relative positional relationship between the screen and the linear sensor. Item 4. The image input device according to any one of Items 1 and 3 .

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