JP2995805B2 - Color parameter setting device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color parameter setting device that sets an optimal color parameter when photographing a subject.

2. Description of the Related Art In a case where a subject is photographed by a television camera and the video signal is processed to inspect the subject, it is necessary to set color parameters so as to obtain an optimal image.

Conventionally, the setting of this color parameter is, for example, the seventh
This was done as shown in the figure.

That is, the subject 3 is placed on the table 4 and the white light source 1
The emitted light is radiated to the subject 3 via the color filter 2. The color parameters are set by exchanging the color filter 2 so that the contrast (difference in shading) between the subject 3 and the table 4 as the background is maximized. By making such settings,
Since the contrast of the video signal output from the video camera is maximized, it is easy to inspect the subject using the video signal.

[Problems to be Solved by the Invention] However, in such a conventional method, since a person visually observes whether or not the contrast is maximized, it takes time to set an optimal color parameter. Not only that, but setting is difficult for non-experts. Also, a plurality of colored filters 2 are prepared,
Since only an appropriate one is selected from among them, the contrast cannot be linearly changed and adjusted, and it is difficult to accurately set the color parameters.

The present invention has been made in view of such a situation, and it is an object of the present invention to set color parameters in a short time and accurately.

[Means for Solving the Problems] A color parameter setting device according to claim 1 is a photographing means for photographing an image of a subject, an illuminating means for illuminating a plurality of colors of light on the subject, and a subject for outputting the photographing means. Processing means for processing the video signal and calculating the contrast, and adjusting the intensity of the light illuminating the subject for each color so that the contrast of the subject is maximized in accordance with the calculation result of the calculating means. And adjusting means for performing the adjustment.

[Operation] In the color parameter setting device according to the first aspect, the intensity of the light illuminating the subject for each color is adjusted so that the maximum contrast is obtained. Therefore, accurately in a short time,
Color parameters can be set.

Embodiment FIG. 1 is a block diagram showing a configuration of an embodiment of a color parameter setting device according to the present invention.

The television camera 11 (photographing means) photographs a subject (not shown) and outputs a video signal corresponding to the image. This video signal is A / D converted by an A / D converter 12 and processed by a processing circuit 13.
Are written in the image memory 14 after the predetermined processing is performed. The image data written in the image memory 14 is read out, D / A converted by the D / A converter 15, and then displayed.
Output to 16. Thereby, the image of the subject is displayed on the display 16.

On the other hand, the CPU 17 (arithmetic means) reads necessary data from the processing circuit 13 and the image memory 14 and performs an arithmetic operation necessary for setting color parameters. Then, the light emitting device 18 is controlled according to the calculation result.

For example, as shown in FIG. 2, the light emitting device 18 includes light sources 22 to 24 (color parameter control means) for generating R, G, and B lights, and a drive circuit 21 for independently driving these light sources. I have.

Next, the operation will be described with reference to the flowchart of FIG.

First, in step 31, the CPU 17 sets a predetermined initial value regarding the brightness for the light sources 22 to 24 of the respective colors. Then, the light sources 22 to 24 are driven via the drive circuit 21 to irradiate light of each color on the subject with predetermined brightness. Next, in step 32, the image data at that brightness is stored in the image memory 14
To memorize. Then, in step 33, the processing circuit 13 is controlled to calculate the contrast. The calculation of the contrast will be described later in detail.

In step 34, the number of times of processing is determined, and when the number of times has not reached the predetermined number, in step 35, the light source 22 to 24 of R, G, B whose processing has not been completed is selected.
Then, in step 36, the number of times of processing for the color is determined. When the number of processings for the color has not reached the predetermined number, in step 37, the weight of the selected light source is increased by one step (the intensity of light generated by the light source is increased by one step), and the light intensity is increased. The lower image is stored in the image memory 14, and the contrast is calculated again in step 38.

Next, in step 39, the previous (in step 33)
Contrast calculated value and this time (in step 38)
The calculated contrast value is compared to determine whether the current contrast value has become larger than the previous contrast value. If the current contrast value is larger than the previous contrast value, the processing after step 36 is repeated. That is, the light intensity of the selected light source is sequentially increased, and the contrast at that time is calculated.

If it is determined in step 39 that the current contrast value is smaller than the previous contrast value, the weight is returned to the previous value in step 40. That is, the light intensity is reduced. Then, the processing after step 36 is repeated.

As described above, the intensity of light at which the peak value of the contrast is obtained is set by the so-called hill-climbing method.

When it is determined in step 36 that the number of times of calculation of the contrast has reached the predetermined value, the process returns to step 35, another light source is selected, and the processing of step 36 and thereafter is repeated.

When it is determined in step 35 that the processing has been completed for all the light sources, the process returns to step 34, and it is determined whether the number of times of processing for all the light sources has reached a predetermined number. If the number has not reached the predetermined number, the processing from step 35 onward is repeated. If the number has reached the predetermined number, the color parameter setting processing ends.

Next, the contrast calculation processing will be described with reference to the flowchart of FIG.

In step 51, first, numerical value (level or density) information of the pixel data is received.
Are set to -∞ and ∞, respectively. In step 53, a predetermined pixel is selected, and in step 54, the data value of the pixel is compared with the data value of the variable MAX. If the pixel value is larger, the pixel value is set to a variable MAX in step 55. When the pixel value is smaller or equal, the variable MAX is left as it is.

Next, in step 56, the data value of the pixel is compared with the data value of the variable MIN. If the pixel value is smaller, the pixel value is set to the variable MIN in step 57. When the pixel value is larger or equal, the variable MIN is left as it is.

In this way, the maximum value of each pixel data is set to the variable MAX
And the minimum value is set to the variable MIN, respectively.

The above processing is repeated for all pixels. Steps
When it is determined at 53 that this process has been completed for all pixels, at step 58 the difference between the variables MAX and MIN is set as contrast.

 FIG. 5 shows the configuration of another embodiment.

In this embodiment, the light emitting device 18 includes R, G, and B colored liquid crystal filters 62 to 64 (color parameter control means).
And a drive circuit 61 that drives these independently. Although not shown, a white light source is provided, and light generated by this light source is supplied to the liquid crystal filters 62 to 64.
The object is illuminated via the.

The CPU 17 controls the liquid crystal filters 62 to 64 via the drive circuit 61.
Are individually driven to control the R, G, and B filter densities. This makes it possible to adjust the intensity of each color emitted to the subject, similarly to the case of controlling the light sources 22 to 24 in the embodiment of FIG.

 FIG. 6 shows the configuration of still another embodiment.

In this embodiment, the processing circuit 13 reads the color density information of each pixel and outputs it to the CPU 17. The CPU 17 calculates the sum of the densities of the respective colors for each pixel as the density of the pixel,
13 (color parameter control means) to multiply the density of each color by a predetermined coefficient (weighting) to change the density of each pixel. Then, a coefficient that maximizes the density difference between pixels (a coefficient that maximizes contrast) is set.

Thus, in this embodiment, the light emitting device is not controlled, and the video signal is directly controlled.

[Effects of the Invention] As described above, according to the color parameter setting device of the first aspect, the intensity of each color of the light illuminating the subject is adjusted so as to obtain the maximum contrast.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a color parameter setting device according to the present invention, FIG. 2 is a block diagram showing the configuration of an embodiment of the light emitting device of FIG. 1, FIG. 3 and FIG. Is a flowchart for explaining the operation of the embodiment of FIG. 1;
5 and 6 are block diagrams showing the configuration of another embodiment of the color parameter setting device of the present invention, and FIG. 7 is a diagram for explaining the operation of the conventional color parameter setting. 1 ... light source, 2 ... color filter, 3 ... subject, 4 ...
... table, 11 ... TV camera (photographing means), 13 ... processing circuit (color parameter control means), 14 ... image memory,
17 CPU (calculation means), 18 Light emitting device, 22 to 24
... Light source (color parameter control means), 62 to 64 ... Colored liquid crystal filter (color parameter control means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06T 5/00 G06T 1/00 H04N 1/40

Claims (1)

(57) [Claims] A photographing means for photographing an image of an object; an illuminating means for illuminating the object with light of a plurality of colors; a video signal of the object output from the photographing means for calculating a contrast. Means, and adjusting means for adjusting the intensity of light for each color of the light emitted from the illumination means to the object so that the contrast of the object is maximized in accordance with the operation result of the operation means. A color parameter setting device.