JPH06308938A - Picture processing device - Google Patents

Abstract

PURPOSE:To provide a picture processing device in which a chroma key procession is performed even for a picture whose color is not uniform such as a natural picture by adopting a chroma key processing of the picture which displays a picture on a display device without color only for a specified part. CONSTITUTION:This picture processing device is provided with upper limit and lower limit detectors 4, 5 specifying a range where the chroma key processing (a transparent processing) for the natural picture is performed with digital picture data having 24 bits, a transparent processing device making the specified range transparent and a selection circuit 7 selecting a natural picture subjected to transparency processing and a range where a background picture is used. The chroma key processing is performed easily by only specifying upper and lower data. Since chroma key processing is performed freely to not only picture data photographed in front of a singe-color background but also to a color which is not used in a part desired to leave as a picture, the degree of freedom of picture expression is much enlarged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image chroma keying process for displaying an image on a display device by extracting a specified portion of a color.

[0002]

2. Description of the Related Art The transparency processing of the conventional image processing must be of a single color like an animation picture, and only one color data can be specified for the portion to be made transparent. For example, with a technology called blue back, when there are two screens, one with a person standing in front of a blue board and the other with a mountain landscape screen, the blue board and the person's screen are superimposed on the landscape screen, and only the blue part is displayed. When it was made transparent by making it transparent, the background changed from a blue board to a mountain, and an image of a person standing in front of the mountain was displayed.

[0003]

However, in the above-mentioned prior art, in the case of an image in which the same color is not necessarily continuous like a natural image, for example, a screen in which a person stands in front of a forest, the background is changed to mountains. Therefore, even if you specify color data to make the forest transparent, there is a similar color such as dark green or light green, so you cannot make the forest transparent even if you specify only one color. Was there. Therefore, the present invention solves such a problem, and an object of the present invention is to make it possible to perform transparent processing even on a non-uniform color such as a natural image.

[0004]

In an image processing apparatus which takes in image data converted into digital data and processes it as display data, image information such as image brightness and hue is taken in as digital image data, An image processing device characterized by designating an upper limit value and a lower limit value of digital data and transparently processing image data in the range.

[0005]

FIG. 1 is a block diagram of an image processing apparatus according to an embodiment of the present invention. In the figure, the upper limit detector 4 and the lower limit detector 5 individually judge the digital image data of the input image as the upper limit image data and the lower limit image data based on the upper limit and the lower limit data, respectively. Are output respectively.

The transparent processing device 6 reads the detection results of both the upper limit detector 4 and the lower limit detector 5 and drives the selection circuit 7.

The selection circuit 7 receives the image data and the background image data, and selects the data to be used for each area according to the detection result of the transparency processing device 6.

By this series of operations, the background image can be displayed at the place where the image data becomes transparent. The image data consists of three image elements Y, U, and V, each of which is 8-bit data, and the image data is 24-bit. These Y, U, and V are three pieces of data, that is, a Y signal representing luminance, a U signal representing color difference information of a purple color, and a V signal representing color difference information of an orange color.

When the data representing the luminance is Y data and expressed in hexadecimal, it has a value from 00h to FFh, where 00h is black,
FFh represents white.

The data representing the color difference information of purple color is U data, has a value from 00h to FFh, and becomes colorless at 80h.

Data representing the color difference information of orange colors is V data and has a value from OOh to FFh, and is 80
It becomes colorless at h.

The data processing is simplified by expressing it as YUV data.

The portion to be made transparent is specified by using this 24-bit color data. At this time, the digital data of the moving image may include an error caused by a calculation error or the like. A single color, that is, a portion where the code represented by 24 bits of digital image data should be the same may be different code. In this case, the specified color is not a single color, so it is necessary to determine the range as the upper limit data and the lower limit data, and specify the binary value for transparent detection.

When the image data expressed in hexadecimal number is input to the upper limit detector 4, the value designated by the upper limit data and the value of the image data are compared with the image data of each pixel, and the value less than or equal to the upper limit data is detected. The image data is output as the upper limit detection result of the image information. When input to the lower limit detector, image information equal to or higher than the value specified by the lower limit data is output as the lower limit detection result.

The detection results output from both detectors are input to the transparency processing device 6, and the portions that share the same upper limit and lower limit detection results are transparently processed. And the selection circuit 7
Determines which of the image data and the background image data is to be output, and outputs one image data in which the background image is displayed in the transparent portion of the image.

The operation of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of an image processing apparatus. Image data having a pattern as shown in FIG. 2A is input from the image data terminal 1 to the upper limit detector 4, the lower limit detector 5, and the selection circuit 7, respectively. This image is a pseudo representation of a gradation in which the right edge is black, and it gradually becomes whiter toward the left, and is represented using only the luminance signal. That is, as the image data, the Y data is uniformly changed from 00h to FFh, and the U and V data are fixed to colorless 80h. In this example, the black and white triangles are only placed on each half of the surface, but originally the ratio of the mixture of black and white is changed, that is, it changes from black to white through the gray process. That is, it does not represent a triangular wave.

Image data of the background image of FIG. 2B is input to the selection circuit 7 from the background image data terminal 2. This picture has triangles lined up in a horizontal row and has all the YUV data. Figure 2 of these two pictures
It is considered that (a) is on top and FIG. 2 (b) is on bottom.

The upper limit detector 4 is assigned a code of A0h of Y data, and the lower limit detector 5 is assigned a code of 50h of Y data. Since the U and V components of the image data are fixed at 80h, the U and V data of the upper limit detector and the lower limit detector are set to 80h. When the image data of FIG. 2A is input, the upper limit detector 4 compares the upper limit data with the image data, and detects the minimum value 00h from A0h of a value equal to or less than the code of the upper limit data. To explain with reference to FIG. 2A, the portion written as A0 is cut vertically and left side is output. The lower limit detector 5 has a maximum value FFh from 50h which is a value equal to or higher than the code of the lower limit data
2A, the right side is output from the position written as 50. Each detection result is input to the transparent processing device.

The transparency processing device 6 outputs a portion between 50h and A0h, which is a sandwiched portion between these detection results, as transparent image data. As described with reference to FIG. 2A, it is determined that the portion between 50 and A0 has become transparent by the transparent processing device 6. This image is the detection result of FIG.

On the other hand, FIG. 2A input to the selection circuit 7
Image data and the image data of the background image in FIG.
The range used as output image data is determined based on the detection result of the transparency processing device 6.

The output image data terminal 3 outputs the image data in which the background image is displayed in the range of 50h to A0h which is transparent processed in FIG.

The result of this series of operations is the output image of FIG. 2 (d), which is a diagram in which the portion 50 to A0 of the moving image of FIG. 2 (a) is transparent processed on the background image of FIG. 2 (b). 2 (c)
The result is a superposed image.

As an application example of this image processing apparatus, another upper limit detector and a lower limit detector are added, and two image data are simultaneously input to the detector to perform transparency processing at two places of the image.
This method can further expand the image processing capability.

In order to make this application example easy to understand, description will be given with reference to FIGS. 3 and 4. FIG. 3 is a block diagram of an image processing apparatus in an application example, in which one upper limit detector and one lower limit detector are added to the circuit of FIG. 1, and one transparent processing device and one selection circuit are provided, but an upper limit detector or 2 detectors
I have each one. The upper limit detector and the lower limit detector on the upper side are collectively referred to as a detector 11, and the upper limit detector and the lower limit detector on the lower side are collectively referred to as a detector 14.

The image data input to the detectors 11 and 14 and the selection circuit 18 shown in FIG. 3 is the image shown in FIG.
It is an image of the same pattern as (a).

The background image data input from the background image data terminal 9 to the selection circuit 18 is the background image of FIG. 4B, and the same background image as that of FIG. 2B is used.

Since the U and V components of the image data input to the detectors 11 and 14 and the selection circuit 18 are fixed at 80h, the upper limit data and the lower limit data of the detectors 11 and 14 are
It is sufficient to fix the U and V data to 80h and specify only the Y data.

The upper limit detector 12 is designated as Y data 60h, and the lower limit detector 13 is designated as Y data 20h.
When the image data of (a) is input, the detector 11 outputs 20
The image data of the portion between h and 60h is detected. Explaining in FIG. 4C, it is the transparent portion on the left side. Further, the upper limit detector 15 has Y data E0h, and the lower limit detector 16 has Y
When A0h of the data is designated and the image data of FIG. 3 is input, the image data detected by the detector 14 is A0h.
To E0h, which is the transparent part on the right side of FIG. 4 (c).

The outputs of all four detectors are transparent processing apparatus 1.
60 from 20h detected by the detector 11
h part and A0h to E0h detected by the detector 14
The image data obtained by transparentizing the portion is output. Figure 4
Explaining in (a), the part from 20 to 60 and A0 to E0
Is judged to be transparent, and is subjected to transparency processing. This transparent processed image data becomes an image like the detection result in FIG.

Then, the selection circuit 18 selects how to use the image data of FIG. 4A and the image data of the background image of FIG. 4B as output image data based on the detection result.

The output image data terminal 10 outputs the image data in which the background image is displayed in the range 20h to 60h and the range A0h to E0h of the transparent processed image.

The result of this series of operations is the output image in FIG. 4 (d), which is shown in FIG. 4 (a) on the background image in FIG. 4 (b).
4C is an image in which the detection results of FIG. 4C in which 20 to 60 and A0 to E0 of the image of FIG.

[0033]

As described above, according to the present invention, the upper limit,
By specifying the lower limit data, you can easily perform chroma key processing, not only image data shot in front of a single color background called blue back, but also colors not used in the part you want to leave as an image. If so, it is possible to freely perform chroma key processing, which greatly expands the degree of freedom in image expression, and has the effect of making image processing with natural images, which has not been used so far, very familiar.

[Brief description of drawings]

FIG. 1 is a basic block diagram of an image processing apparatus of the present invention.

FIG. 2 is a basic image processing diagram of the present invention. (A) A figure showing a natural image. (B) A figure showing a background image. (C) A figure showing a detection result. (D) A figure showing an output image.

FIG. 3 is a block diagram of an image processing apparatus in an application example of the present invention.

FIG. 4 is an image processing diagram in an application example of the present invention. (A) A figure showing a natural image. (B) A figure showing a background image. (C) A figure showing a detection result. (D) A figure showing an output image.

[Explanation of symbols]

 1-3, 8-10 I / O pins 4-5, 11-16 Detector 6, 17 Transparent processing device 7, 18 Selection circuit

Claims (2)

[Claims] 1. An image processing apparatus that takes in image data converted into digital data and processes it as display data, takes in image information such as image brightness and hue as digital image data, and sets the upper limit of the digital data. An image processing apparatus, wherein a value and a lower limit value are designated, and image data in the range is subjected to a transparent process. 2. By designating a plurality of upper limit values and lower limit values of digital image data and further having a plurality of transparent processing means,
An image processing device characterized by performing transparency processing at a plurality of locations.