JPH06326930A - Picture processor - Google Patents

Abstract

PURPOSE:To pick up the image of the whole area of a subject to be checked, to expand a damage part and to improve resolution by providing a picture processor with a two-dimensional image pickup element, finely moving the image pickup element with a step shorter than a pitch between picture elements so as to locate it on plural image pickup positions and picking up the image of the subject to be checked by the image pickup element on each position. CONSTITUTION:The picture processor is constituted of the two-dimensional image pickup element 1, a moving device 2, a storage device 3, a picture processing part 4, and a control part 5. The element 1 is constituted of a picture element aggregate 7 consisting of plural picture elements arrayed in the X-axis and Y-axis directions and the device 2 is constituted of an X-axis direction moving piezo-electric actuator 8 and a Y-axis direction moving actuator 9. The processing part 4 is constituted of a computer e.g. for extracting required parts from plural data stored in the device 3 and synthesizing these extracted parts. The control part 5 is also constituted of a computer to control the operation of the device and the reading operation or the like of picture data picked up by the element 1. In such a constitution, an expansion frame F is arranged on an image pickup position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus applied to the field of measurement such as visual inspection.

[0002]

2. Description of the Related Art As an image processing apparatus of this type, there is known an image processing apparatus including a two-dimensional image pickup device having a pixel assembly composed of a plurality of pixels in two orthogonal axes.

The resolution of a two-dimensional image pickup device is limited by the number of pixels, and in general, in order to realize highly accurate measurement, a high-magnification lens is used and only a desired region is magnified and imaged. A method of applying treatment is used.

[0004]

In the image processing apparatus as described above, when the ratio of the size of a flaw to the area to be imaged is sufficient, the entire apparatus can be simplified and is very practical. However, if this is not the case, that is, if it is necessary to image over the entire area of the object to be inspected and the size of the flaw or the like is sufficiently smaller than the size of the object to be inspected, the resolution will naturally be limited.

The object of the present invention is to solve the above problems,
An object of the present invention is to provide an image processing device capable of sufficiently increasing the resolution of a desired portion in all cases.

[0006]

SUMMARY OF THE INVENTION An image processing apparatus according to the present invention is a two-dimensional image sensor having a pixel group consisting of a plurality of pixels in the two orthogonal directions, and the two-dimensional image sensor is minute in the two orthogonal directions. A moving device that moves and positions it at a plurality of image capturing positions, a storage device that stores image data captured by the two-dimensional image sensor at the plurality of image capturing positions, and a plurality of image data stored in the storage device. An image processing unit for extracting and synthesizing a desired portion from the inside, and a control unit for controlling the operation of the moving device and the reading operation of the image data picked up by the two-dimensional image pickup device are provided.

[0007]

The two-dimensional image pickup device is finely moved by a step amount smaller than the inter-pixel pitch and positioned at a plurality of image pickup positions. Then, the object is imaged by the two-dimensional imaging element at each imaging position, and the image data is stored in the storage device. At this time, the entire area of the object to be inspected can be imaged. By extracting and synthesizing a desired portion from the plurality of image data stored in the storage device, only the desired portion is enlarged and its resolution is enhanced. Therefore, even when the size of a flaw or the like is sufficiently smaller than the size of the test object, the entire area of the test object is imaged and a desired portion such as a flaw is sufficiently enlarged to provide a sufficient resolution. Can be increased.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic structure of an image processing apparatus.

In FIG. 1, the image processing apparatus includes a CCD image pickup device (two-dimensional image pickup device) (1), a moving device (2), a storage device (3), an image processing unit (4) and a control unit (5). I have it.

The image pickup device (1) is, as shown in detail in FIGS. 2 and 3, orthogonal two-axis directions, that is, the X-axis direction (lateral direction).
And a pixel aggregate (7) including a plurality of pixels (6) in the Y-axis direction (vertical direction). FIG. 2 shows the whole pixel assembly (7), and FIG. 3 shows a part of it in an enlarged scale. The number of pixels (6) in both the X and Y directions is 512, respectively.
The position of is expressed using the column address [Y] (0 to 511) in the Y-axis direction and the column address [X] (0 to 511) in the X-axis direction. The column address [X] increases toward the right, and the column address [Y] increases toward the bottom.
The pixel pitches p in both the X and Y directions are equal.

The moving device (2) is for moving the image pickup device (1) minutely in the X-axis direction and the Y-axis direction to position it at a plurality of image pickup positions. For example, a piezoelectric actuator (8) for moving in the X-axis direction is used. ) And an actuator for moving in the Y-axis direction
(9) is provided.

The storage device (3) stores image data picked up by the image pickup device (1) at a plurality of image pickup positions, and includes a frame memory for capturing.

The image processing section (4) is for extracting a desired part from a plurality of image data stored in the storage device (3) and synthesizing it, and is constituted by a computer, for example. The image processing unit (4) is provided with a synthesizing frame memory for storing the data synthesized as described above.

The control section (5) controls the operation of the moving device (2) and the reading operation of the image data picked up by the image pickup element (1), and is constituted by, for example, a computer.

The image processing unit (4) and the control unit (5) may be configured by a common computer.

In this embodiment, the image sensor (1) is
It is positioned at four imaging positions by the moving device (2). FIG. 4 shows the position of one pixel (6) at four image pickup positions. The imaging element (1) is positioned at the first imaging position (initial position), then moved downward in the Y-axis direction to be positioned at the second imaging position, and is moved from the second imaging position to the X position.
It is moved to the right in the axial direction and is positioned at the third imaging position, is moved upward from the third imaging position in the Y-axis direction to be positioned at the fourth imaging position, and is moved leftward from the fourth imaging position in the X-axis direction. It is moved and returned to the first imaging position. The movement step amount of the image sensor (1) in the X-axis direction and the Y-axis direction is
It is half the pixel pitch p (p / 2). In the following description, the symbol a represents the first image capturing position, the symbol b represents the second image capturing position, the symbol c represents the third image capturing position, and the symbol d represents the fourth image capturing position. In FIG. 4, the solid line with the symbol a is the pixel (6) at the first image capturing position, the broken line with the symbol b is the pixel (6) at the second image capturing position, and the symbol c is attached. The broken line shows the pixel (6) at the third image pickup position, and the broken line with the reference sign d shows the pixel (6) at the fourth image pickup position.

Next, an example of the operation of the above image processing apparatus will be described with reference to the flow charts of FIGS.
5 shows the first half of the operation, and FIG. 6 shows the second half.

First, the enlargement frame (F) as shown in FIG. 2 is set (step 1). The enlargement frame (F) is set by the minimum value X _s and the maximum value X _e of the column address of the portion to be enlarged.
And the minimum value Y _s and the maximum value Y _e of the stage address are set to desired values. Then, the image pickup device (1) is positioned at the first image pickup position, and 1 is set to the variable N representing the image pickup position (step 2). Next, the Nth
The object is imaged by the image sensor (1) at the position, the image data is captured, and frm [0] [0] to frm [511] of the frame memory for capturing of the storage device (3).
It is stored in [511] (step 3). frm [y]
[X] represents each memory unit of the frame memory for capturing, [X] represents a column address, and [Y] represents a column address. The frm [Y] [X] stores the luminance data of the pixel (6) at the column address [X] and the stage address [Y]. Next, the value of N is checked (step 4), and if it is 1, the process proceeds to step 5. If the value of N is not 1 in step 4, the process proceeds to step 6, and if the value of N is 2, the process proceeds to step 7. N in step 6
If the value of is not 2, the process proceeds to step 8, and if the value of N is 3, the process proceeds to step 9. If the value of N is not 3 in step 8, proceed to step 10. In step 5,
The variables i and j are each set to 0, and the process proceeds to step 11. In step 7, i is set to 0 and j is set to 1,
Go to step 11. In step 9, i and j are set to 1, and the process proceeds to step 11. In step 10, i is set to 1 and j is set to 0, and the process proceeds to step 11.
At step 11, the variable Y is set to Y _s and the variable n is set to 0. Next, X _s is set to the variable X and 0 is set to the variable m (step 12). Next, the luminance data of frm [Y] [X] is set to mem [2n + j] [2m + i] (step 13). mem [Y] [X] represents each memory unit of the compositing frame memory for enlarged display, [X] represents a column address, and [Y] represents a column address.

Next, X and X _e are compared (step 1
4) If X is less than X _e , go to step 15,
X + 1 is set to X and m + 1 is set to m, and the process returns to step 13. If X is greater than or equal to X _e in step 15, the process proceeds to step 16, Y and Y _e are compared, and if Y is smaller than Y _e , the process proceeds to step 17 and Y
+1 is set to Y and n + 1 is set to n, and the process returns to step 12. If Y is greater than or equal to Y _e in step 16, then step 18 is entered and N and 4 are compared,
If N is less than 4, proceed to step 19
The minute movement of (1) is performed, N + 1 is set to N, and the process returns to step 3. If N is 4 or more in step 18, the process proceeds to step 20, and the image data in the enlargement frame (F) is enlarged and displayed by using the composing frame memory (mem [Y] [X]), and the processing is performed. Ends.

FIG. 7 shows pixels (6) in the enlargement frame (F) when the image sensor (1) is positioned at the first to fourth image pickup positions.
Represents the position of. In this case, 3 columns in the X-axis direction, Y
The portion including the pixel (6) of three steps in the axial direction is the expansion frame (F),
Pixels (6) in the top 3 rows are numbered 1, 2 and 3 from the left, and pixels (6) in the middle 3 rows are 4, 5 and 6 in order from the left.
The pixels (6) in the bottom three columns are numbered 7, 8 and 9 from the left. Of the two-digit code assigned to each pixel (6), the upper digits 1 to 9 represent the pixel (6) number, and the lower letters a, b, c, and d represent the above-mentioned imaging position. There is. FIG. 8 shows the composing frame memory corresponding to the pixel (6). The numbers 0 to 5 above the upper six memory units (10) in FIG. 8 represent column addresses, and the numbers 0 to 5 on the left of the left six memory units (10) represent column addresses. In addition, the brightness data stored in each memory unit (10) is shown. The luminance data is represented by the letter I with a two-digit subscript indicating the number of the pixel (6) and the imaging position.

By executing the operations of the flowcharts of FIGS. 5 and 6, the luminance data of the pixel (6) in the enlargement frame (F) taken in at the four image pickup positions are combined,
The combined data is stored in the combining frame memory as shown in FIG.

That is, first, the image pickup device (1) is positioned at the first image pickup position, and the luminance data of the pixel (6) at the first image pickup position is fetched in the frame memory for fetching.
At this time, within the enlargement frame (F), the pixels (6) of 1a to 9a
The luminance data I _{1a to} I _{9a of} are stored in the corresponding memory unit of the frame memory. The luminance data I _{1a to} I _9a of the pixels _{1a to 9a} correspond to the enlargement frame (F), and the vertical and horizontal every other memory unit of the composing frame memory, that is, the addresses [0], [0], and [0]. [2], [0] [4], [2]
[0], [2] [2], [2] [4], [4] [0],
It is stored in the memory unit (10) of [4] [2], [4] [4], respectively. Next, the image pickup device (1) is positioned at the second image pickup position, and similarly, the pixels 1b to 9b at the second image pickup position are arranged.
The luminance data I _{1b to} I _{9b of} (6) are the memory unit corresponding to the capture frame memory, and the vertical and horizontal alternate memory of the composing frame memory corresponding to the expansion frame (F), that is, the address [1]. [0], [1], [2], [1]
[4], [3] [0], [3] [2], [3] [4],
It is stored in the memory unit (10) of [5] [0], [5] [2], [5] [4], respectively. Next, the image pickup device (1) is positioned at the third image pickup position, and similarly, the luminance data I _{1c to} I _9c of the pixels (6) _{1c to 9c at} the third image pickup position correspond to the frame memory for capturing. Memory unit, and every other vertical and horizontal memory of the composition frame memory corresponding to the expansion frame (F), that is, addresses [1], [1], [1]
[3], [1] [5], [3] [1], [3] [3],
[3] [5], [5] [1], [5] [3], [5]
It is stored in the memory unit (10) of [5]. Finally, the image pickup device (1) is positioned at the fourth image pickup position, and similarly, the luminance data I _{1d to} I _9d of the pixels (6) _{1d to 9d at} the fourth image pickup position correspond to the capture frame memory. Memory unit, and every other vertical and horizontal memory of the compositing frame memory corresponding to the expansion frame (F), that is, addresses [0] [1], [0] [3], [0] [5], [ 2]
[1], [2] [3], [2] [5], [4] [1],
It is stored in the memory unit (10) of [4] [3], [4] [5], respectively. In this way, the pixels at each imaging position
The luminance data of (6) is stored in every other vertical and horizontal memory units (10) of the composition frame memory, and the luminance data of the pixel (6) at the second imaging position is the pixel (6) at the first imaging position. The pixel (6) at the third imaging position is stored in the memory unit (10) immediately below the memory unit (10) in which the luminance data of is stored.
Luminance data is stored in the memory unit (10) immediately to the right of the memory unit (10) in which the luminance data of the pixel (6) at the second imaging position is stored, and the pixel (6) at the fourth imaging position is stored. The luminance data of is the memory unit (10) immediately above the memory unit (10) in which the luminance data of the pixel (6) at the second imaging position is stored.
Memorized in. Therefore, the composite data stored in the composition frame memory is the same as the image data when it is assumed that the pixels (6) are arranged at a pitch of half (p / 2) of the actual inter-pixel pitch p as shown in FIG. Is the same. Since the pitch between the pixels (6) at the four image pickup positions is half the actual pitch p, the composite data stored in the composition frame memory has twice the resolution of the actual pixel aggregate (7). If the image is displayed using this, an image in which the image in the enlargement frame (F) is enlarged twice in the vertical and horizontal directions can be obtained.

The storage device (3) may be provided with at least one frame memory for capturing. If only one frame memory for capture is provided, the contents of the frame memory for capture are updated each time the image sensor (1) is moved to a different position and the image sensor (1) is replaced by four.
If you can only magnify the contents of one magnifying frame (F) when you perform a series of images by positioning at one imaging position, and you want to magnify the other magnifying frames,
It is necessary to take an image again. If four capturing frame memories are provided and the image data at each image capturing position is stored in a separate capturing frame memory, the image sensor (1) is positioned at four image capturing positions to perform a series of image capturing. After that, the image data stored in the four frame memories for capturing can be used to enlarge and display an arbitrary enlargement frame as many times as necessary without taking an image.

In the above embodiment, since the image pickup device (1) is moved at a pitch half the pixel pitch p, the resolution can be doubled. However, the movement pitch of the image pickup device (1) is increased. By further reducing, the resolution can be further increased. Further, in the above embodiment, for the sake of explanation, the width of the dead area between the pixels (6) of the image sensor (1) is displayed to be almost equal to the width of the pixel (6). Even if is smaller than the width of the pixel (6), the processing is similar.

[0026]

According to the image processing apparatus of the present invention, as described above, even when the size of a flaw or the like is sufficiently smaller than the size of the test object, the entire test object is imaged, Moreover, it is possible to sufficiently enlarge a desired portion such as a flaw and sufficiently improve the resolution. Further, it is only necessary to add a mechanism for moving a commercially available two-dimensional image pickup device, no special hardware is required, and enlarged display of an arbitrary area of the screen can be performed by a relatively simple algorithm.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an image processing apparatus showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a pixel aggregate of a two-dimensional image sensor.

FIG. 3 is an explanatory diagram showing a part of the pixel aggregate of FIG. 2 in an enlarged manner.

FIG. 4 is an explanatory diagram showing a moving state of one pixel.

FIG. 5 is a flowchart showing a first half part of an example of an image processing operation.

FIG. 6 is a flowchart showing the latter half of an example of the image processing operation.

FIG. 7 is an explanatory diagram showing a state of movement of pixels in the enlargement frame.

FIG. 8 is an explanatory diagram showing an example of a composition frame memory and composition data stored therein.

[Explanation of symbols]

 (1) CCD image pickup device (two-dimensional image pickup device) (2) Moving device (3) Storage device (4) Image processing unit (5) Control unit (6) Pixel (7) Pixel assembly

Claims (1)

[Claims] 1. A two-dimensional image pickup device having a pixel aggregate composed of a plurality of pixels in two orthogonal axes, and a moving device for finely moving the two-dimensional image pickup device in the two orthogonal directions to position a plurality of image pickup positions. A storage device for storing image data captured by the two-dimensional image sensor at the plurality of image capturing positions; an image for extracting and combining a desired portion from the plurality of image data stored in the storage device An image processing apparatus comprising: a processing unit; and a control unit that controls the operation of the moving device and the operation of reading the image data captured by the two-dimensional image sensor.