JPH0682233A - Color image processor - Google Patents

Abstract

PURPOSE:To provide a color image processor which enables accurate detection of an object by removing effect of changes in external conditions such as light ing to stabilize the detecting conditions. CONSTITUTION:A correction computing section 18 compares the gradation of a reference area from an illuminance detection section 12 with the reference gradation of a reference illuminance memory 19 to determine variation of illuminance, and correction values of the conditions of lighting by lighting devices 15, 16 and 17 are calculated so that the gradation in the control area is stabilized to the reference gradation. A control circuit section 20 controls the lighting devices 15, 16 and 17 of respective colors based on the correction values to adjust light sources of the lighting devices 15, 16 and 17 thereby achieving stabilization of the gradation in the control area to the reference gradation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus for detecting an image of a target detection target in a detection area based on a color image obtained by picking up a predetermined detection area.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional color image processing apparatus of this type includes an image pickup device 1 using a CCD two-dimensional color image sensor or the like, and the image pickup device 1 picks up an image of a required spatial region. The image signal output from the image pickup apparatus 1 is input to the video signal processing unit 2 which also serves as a color separation unit, and is separated into three color image signals of R (red), G (green), and B (blue). After that, it is converted into a digital signal by the A / D conversion circuit 3 and input to the comparison circuit 4. As shown in FIG. 5, the inspection area designating unit 4 sets a detection area W ₁ including an image of the detection object X in the spatial area imaged by the imaging device 1.

Thus, in the image signal output from the A / D conversion circuit 3, the detection area W ₁ is designated by the detection area designating section 4, and only the pixels within the designated detection area W ₁ are compared circuit 4. Then, the comparison is made with the predetermined threshold value stored in the threshold value memory 7 based on the reference gradation corresponding to the detection region W ₁ stored in the reference gradation memory 8. That is, the threshold memory 7 stores the upper limit value and the lower limit value of the gradation range set for the target detection object X for each color of R, G, B, and the detection area designating unit 4 For the pixel in the detection area W ₁ designated by
For each color of B, it is determined whether the gradation is above the lower limit and below the upper limit, and if the gradation of that pixel is within the gradation range set for all colors, the pixel targeted for detection To output the image signal. Here, the gradation is set to, for example, 8-bit gradation (256 gradations from 0 to 255). Further, in the gradation range, R is 50 to 100 and G is
Is set to 100 to 150, B is set to 200 to 255, and the like. The counter circuit 9 counts the number of pixels targeted for detection from the image signal output from the comparison circuit 4, and the measurement processing unit 10 that constitutes processing means together with the counter circuit 9 performs measurement based on the counted number of pixels. The area and center of gravity of the detection object X are obtained.

The digital signal A / D-converted for each color of R, G, B is D / A-converted by the D / A conversion circuit 11 and becomes an analog image signal to be displayed on the CRT 12. There is.

[0005]

In the above-mentioned conventional configuration,
When the brightness of the illumination changes, for example, when the brightness of the illumination changes, the gradation level of the image signal changes even if the threshold of extracting the pixels of the detection target X is different.
Since the gradation levels of the G and B signals also change, there is a problem in that the detection target cannot be accurately detected with the set threshold value.

Further, in order to eliminate this change in the external condition, it takes a lot of labor and cost, and there is a practical problem.
The present invention has been made in view of the above problems, and its object is to eliminate the influence of changes in external conditions such as illumination and stabilize the detection conditions to enable accurate detection of the detection target. The present invention provides a color image processing device.

[0007]

In order to achieve the above object, an image pickup means for picking up a color image of an object to be detected and an image signal output from the image pickup means are output in a plurality of colors. A signal processing means for separating into an image signal and performing A / D conversion, a detection area designating means for designating a detection area in which an image signal of each color is desired to be detected in the entire image area, and each color set in the designated detection area. Comparing means for comparing the threshold value of the gradation range with the gradation of each color for the pixels in the detection area, and the number of pixels of the pixels in the detection area whose gradation for each color falls within the gradation range. In a color image processing apparatus including a processing unit that counts and processes, an illumination unit of each color that irradiates a detection target with light of a light color corresponding to each of the separated colors, and a measurement in the entire image region Detects changes in illuminance under conditions A change in the illuminance of each color by comparing the detected illuminance of the illuminance detecting means with the illuminance of each color from the image of the reference area set in order to compare the detected illuminance of the illuminance detecting means with the preset illuminance of each color It comprises a correction calculation means for obtaining the amount and the correction amount of the illuminance of each color, and a control means for controlling the brightness of the light source of the illumination means based on the correction amount obtained by the correction calculation means.

According to the second aspect of the invention, the correction calculation means performs the calculation operation with an external timing signal.

[0009]

According to the first aspect of the invention, the illumination means of each color for irradiating the object to be detected with the light of the light color corresponding to each color to be separated and the illuminance change of the measurement condition in the entire image area are detected. The illuminance detection means for detecting the illuminance of each color from the image of the reference area set for this purpose, and the illuminance of each color by comparing the detected illuminance of the illuminance detection means with the preset illuminance of each color. And the control means for controlling the brightness of the light source of the illuminating means on the basis of the correction amount calculated by this correction calculation means. Even if the illuminance of the detection target changes, the illuminance of the separated color can be corrected, and thus the pixel corresponding to the detection target can be accurately extracted. Further, since the ambient illuminance is detected by the illuminance detection means, the illuminance can be detected separately from the inspection of the detection target, so the process of detecting the illuminance and the process of inspecting the detection target are processed in parallel. It will be possible.

According to the second aspect of the present invention, since the correction calculation means performs the calculation operation by the external timing signal, it is necessary to change the light source, start the process, set time in the morning and day, etc. Sometimes, a correction timing signal may be generated by a manual operation or automatic control by a timer to perform the correction calculation, and the time required for the correction calculation can be reduced as compared with the case where the correction calculation is performed for each detection object.

[0011]

EXAMPLES The present invention will be described below with reference to examples. FIG. 1 shows an apparatus according to one embodiment, and the basic configuration of the illustrated embodiment is the same as that of the conventional example, and the circuit parts which perform the same function are designated by the same reference numerals. In addition, in this embodiment, in order to illuminate the inspection object X, illumination devices 15, 16 and 17 for illuminating with R, G and B light colors are provided. As shown in FIG. 2, the illuminators 15, 16 and 17 detect the light from the white light sources L ₁ , L ₂ and L ₃ through the optical filters FR, FG and FB of the respective colors of R, G and B and detect the object X to be detected. It is designed to irradiate.

A CCD two-dimensional color image sensor
The whole image area imaged by the imaging device 1 using
Similar to the above-mentioned conventional example, the detection area including the image of the detection object X
Area W ₁Is specified by the detection area designating unit 4 as in the past.
As shown in FIG. 3, the detection area W₁Different from
, A reference region W including one or more pixels in the background of the detection object X
₂Is set. Here, the reference area W
₂Is composed of one pixel including three colors. Also, as described below
So that the reference area W₂Depending on the pixel gradation of
In order to control the units 15, 16 and 17, the reference area W₂
Is an object (gray etc.) that can obtain the same standard gradation (illuminance).
Achromatic color is desirable).

The image signal corresponding to the pixel in the reference area W ₂ is converted into a digital signal by the A / D conversion circuit 13 and then input to the illuminance detection section 14. The illuminance detection unit 14 obtains a moving average value of gradations of pixels in the reference area W ₂ and stores the moving average value. Here, the reference area D
_{Since 2} is one pixel, it is sufficient to obtain the gradation only for that pixel. However, when the reference area D ₂ is composed of a plurality of pixels, the illuminance detection unit 14 inputs R, G, Using the digital signal of each color of B, the average value of the gradation of the previous data, for example, 16 times before is always calculated from the latest data and stored as the gradation of the reference area W ₂ . The timing of sampling the moving average value may be set appropriately according to the situation.

On the other hand, the correction calculation section 18 which is the correction calculation means.
Then, the standard gradation of the reference area W ₂ set and stored in the standard illuminance memory 19 is compared with the gradation of the reference area W ₂ stored in the illuminance detection unit 12, and the gradation of each color, That is, the amount of change in illuminance is calculated, and the correction amount of the illumination condition by the illumination devices 15, 16 and 17 is calculated so that the gradation of the reference area W ₂ is stabilized at the standard gradation.

This correction amount is given to the control circuit unit 20, and the control circuit unit 20 controls the illuminating devices 15, 16, 17 for each color based on the correction amount to control the respective light sources L ₁ , L ₂ , L ₃ . Dimming. For example, when the gradation of R in the reference area W ₂ rises due to a change in some external condition, the R illumination device 15
That is, the brightness level of the light source L ₁ is reduced to reduce the illuminance of R and stabilize the reference gradation. This dimming control may be converged within a predetermined range (condition) with respect to the reference gradation by applying feedback several times at appropriate times.

The operation control of each part is performed by the CPU 6,
Further, the description of the operation of each circuit section that performs the same function as the conventional example is omitted. Even if the external conditions change as described above, the change is captured in the reference region W ₂ , and the illumination devices 15 and 16 of the target color are fed back by feedback so as to return to the standard gradation.
By controlling the dimming of the light sources L ₁ , L ₂ , and L ₃ of 17, the detection target X can be stably detected even when the external conditions change. In particular, it is unclear what color temperature light is emitted to the detection object X due to the influence of ambient light, but it is easily handled by individually controlling the illumination of each light color of R, G, B. You can do it.
By the way, although the above-mentioned correction is automatically performed, if the correction calculation in the correction calculation unit 13 is performed only when the correction timing signal T from the outside is input,
For example, when changing the light source for lighting, when starting up the process, in the morning
It can be arbitrarily corrected when necessary such as the set time of day.

[0017]

According to the first aspect of the invention, the illumination means of each color for irradiating the object to be detected with the light of the light color corresponding to each color to be separated and the illuminance change of the measurement condition in the entire image area are detected. The illuminance detection means for detecting the illuminance of each color from the image of the reference area set for this purpose, and the illuminance of each color by comparing the detected illuminance of the illuminance detection means with the preset illuminance of each color. And the control means for controlling the brightness of the light source of the illuminating means on the basis of the correction amount calculated by this correction calculation means. Even if the illuminance of the object to be detected changes, the illuminance of the separated color can be corrected, so that the pixels corresponding to the object to be detected can be accurately extracted, and the ambient illuminance is detected by the illuminance detecting means. To be detected Since the inspection separately detect the illuminance and the process of inspecting the detected object and the processing for detecting the illuminance there is an effect that it is possible to process in parallel.

According to the second aspect of the present invention, since the correction calculation means performs the calculation operation by the external timing signal, it is necessary to change the light source, start the process, set time of morning and day, etc. At times, it is possible to generate a correction timing signal by a manual operation or an automatic control by a timer to perform the correction calculation, so that the time required for the correction calculation can be reduced as compared with the case where the correction calculation is performed for each detection object. There is.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a positional relationship between a light source and a detection target of the illumination device of the above.

FIG. 3 is a diagram illustrating a reference area of the above.

FIG. 4 is a block diagram showing a conventional example.

FIG. 5 is a diagram illustrating a detection area of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Imaging device 2 Video signal processing unit 3 A / D conversion circuit 4 Detection area designation unit 5 Comparison circuit 6 CPU 7 Threshold memory 8 Reference gradation memory 9 Counter 10 Measurement processing unit 13 A / D conversion circuit 14 Illuminance detection unit 15 to 17 Lighting Device 18 Correction Calculation Section 11 Reference Gradation Memory 19 Reference Illuminance Memory 20 Control Circuit

Claims (2)

[Claims] 1. An image pickup means for picking up a color image of an object to be detected, a signal processing means for separating an image signal output from the image pickup means into image signals of a plurality of colors and A / D converting the image signal, and an entire image area. Inspection area designating means for designating a detection area in which an image signal of each color is desired to be detected, a gradation range threshold value for each color set in the specified detection area, and a gradation for each color of pixels in the inspection area In the color image processing apparatus, the color image processing apparatus includes: a comparison unit that compares the pixel number in the inspection region and a processing unit that counts and processes the number of pixels having a gradation within the gradation range for each color among the pixels in the inspection region. Illuminating means of each color for irradiating the detection object with light of a light color corresponding to each color to be separated, and of each color from the image of the reference area set to detect the illuminance change of the measurement condition in the entire image area. Illuminance to detect illuminance Outputting means, a correction calculation means for comparing the detected illuminance of the illuminance detecting means and the preset illuminance of each color to obtain the amount of change in the illuminance of each color, and calculating the amount of correction of the illuminance of each color, A color image processing apparatus comprising: a control unit that controls the brightness of the light source of the illumination unit based on the correction amount obtained by the correction calculation unit. 2. The color image processing apparatus according to claim 1, wherein the correction calculation means performs a calculation operation with an external timing signal.