JPH07141493A - Picture processor - Google Patents

Abstract

PURPOSE:To synthesize pictures without mixing a chroma key color in synthesized picture by taking the boundary part as the background area in the non- background area which is not separated well as the background area. CONSTITUTION:The device is provided with a picture storage part 1 which stores picture data and a background setting part 2 which sets the background area for the picture data stored in the storage part 1. With the part 2, the background area and the other non-background area are separated. The boundary part with the background area in the non-background area is removed off by a boundary removing part 3 while taking into account the state of the nearby pixel of the noted one. By taking it as the background area, the chroma key color to be appeared in the boundary part in the non-background area is regarded as the background area. Thus, a picture synthesizing part 4 synthesizes pictures without being affected by the chroma key.

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 which cuts out a specific area of a given image and synthesizes it with another image.

[0002]

2. Description of the Related Art Conventionally, various methods have been put into practical use for cutting out a background region from an image. For example, there are a method of manually cutting out using a mouse, a light pen, etc., and a method of cutting out a specific hue called a chroma key method as a background color.

[0003]

In the above-mentioned conventional technique, it is very troublesome to separate the boundaries with high precision in the manual cutting method. In the chroma key method, for example, if there is a portion having the same hue as the background area in the area other than the background area, the portion is recognized as the background, or the output of the TV camera is A / D converted and captured. When this is done, there is a problem in that the hue becomes violent where there is a strong edge, the boundary portion cannot be separated into the background area and the non-background area, and the chroma key color is mixed in the composite image.

The present invention is intended to solve the above-mentioned problems of the prior art, and the boundary area between the background area and the non-background area that cannot be separated well is set as the background area.
It is an object of the present invention to provide an image processing apparatus capable of performing image composition without mixing chroma key colors in a composite image.

[0005]

According to the present invention, in an image processing apparatus which cuts out a non-background area of a given image, synthesizes it with another image, and outputs it, an image storage section for storing image data and a background area are provided. In the background setting part to be set, in the set background region and non-background region, the boundary part of the non-background region is scraped off based on a predetermined rule, and the boundary deleting part to be incorporated in the background region, and the obtained non-background region are separated. An image processing apparatus including an image combining unit that combines images and generates a combined image.

[0006]

According to the present invention, the image stored in the image storage unit is subjected to the process of separating the background region and the non-background region in the background setting unit. At that time, if the parameter of the background to be set is strict, the influence of the background appears on the boundary part of the non-background area. If the parameter is loosened, a part of the non-background area may be regarded as the background area. In the former case, the influence always occurs at the boundary portion between the background area and the non-background area, so the boundary deleting unit performs processing for changing the boundary portion of the non-background area to the background area. After that, the image in the non-background area is combined with another image by the image combining unit, so that the image can be combined without the influence of the background area.

[0007]

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the invention described in claim 1. In the figure, 1 is an image storage unit for storing image data, 2 is a background setting unit for setting a background area for the image data stored in the image storage unit 1,
3 is a boundary deleting unit for incorporating a boundary portion between the background region and the background region in the non-background region set in the background setting unit 2 into the background region, and 4 is an image of the obtained non-background region. It is an image synthesizing unit that fits and synthesizes another image stored in the image storage unit 1 to generate a synthetic image.

The image storage unit 1 stores, for example, an image captured by A / D converting a signal from a television camera or an image captured by using a scanner. This uses 8 bits for each of RGB for each pixel (pixel) with 8 bits added for work for area setting. In the case of the present embodiment, the working 8 bits are used for background setting and 1 bit for boundary setting. In addition, the capacity of the entire image storage unit 1 needs to be able to store a plurality of images because it is necessary to store an intermediate result of each process and an image for composition.

In the background setting unit 2, for example, when the background area is separated using the hue, each pixel of the image (Equation 1)
The calculation is performed using the formula of, which is, for example, {π ± (π / 8)}
The background setting bit is set to 1 if it is in a certain range, and this bit is set to 0 if it is not.

[0011]

[Equation 1] Hue = cos ^-1 {(2R-GB) / (2√ [(RG) ² + (R
-B) (GB)])} However, if B> G, hue = 2π−hue Further, when the image is a black and white image, the above-mentioned processing is performed using lightness instead of hue. That is, when each value of RGB is in the range of 64 ≦ R <96 64 ≦ G <96 64 ≦ B <96, the background setting bit is set to 1
If not entered, this bit is set to 0.

An example of the image thus obtained by the background setting unit 2 is shown in FIG. For example, when a signal from a TV camera is A / D-converted and captured, the hue is violent at a strong edge portion, and the background color remains at the boundary between the background area and the non-background area as shown in FIG. , The shape of the boundary is wavy.

Therefore, the boundary deleting unit 3 performs a process of regarding the boundary portion of the non-background area as a background area. That is, as shown in the flowchart of FIG.
For each pixel of the image obtained by (step S
1, S8), if the background setting bit is 0, that is, a non-background area (step S2), the background setting bits of 8 points in the vicinity of 1 are checked (step 3), and for example, 2 out of 8 points are set.
If the bit of the point is 1 (step S4), it is determined that the pixel is the boundary part of the non-background area, and the boundary setting bit is set to 1 (step S5). Otherwise, the boundary setting bit is set to 0 (step S6). These processes are performed for all pixels (steps S7, S
8). After that, all pixels (steps S9, S1
2, S13), the pixel for which the boundary setting bit is 1 is changed (step S10), and the background setting bit is changed from 0 to 1 (step S11).

In some cases, it may be more effective to perform this boundary deletion processing a plurality of times depending on the performance of the device when capturing an image. An example of the image obtained by this processing is shown in FIG.

Next, the image synthesizing unit 4 performs a synthesizing process of the image a obtained by the above method and the image b stored in another area of the image storage unit 1. This is because when the image a is combined at an arbitrary position in the image b, for each pixel of the image a, if the background setting bit is 0, the pixel of the image b is replaced with the image a, and if the background setting bit is 1. If you do nothing. This may be done for all pixels of the image a. It should be noted that in the case of this processing, the image changes abruptly at the boundary portion, resulting in an unnatural image. Therefore, in each pixel of the image a, the ratios of 0 and 1 of the background setting bits of 9 points in the vicinity of 1 including the self are checked, and the images a and b are combined according to the ratio. For example, in a certain pixel (R _a G _a B _a ) of the image a, if the ratio of the bits for background setting at 9 points in one neighborhood is 0 for n points and 1 for (9−n) points, on the image b Pixels to be combined (R _b G
_b B _b ) is calculated by the equation (2).

[0016]

## EQU2 ## R _b = n × R _a ÷ 9 + (9−n) × R _b ÷ 9 G _b = n × G _a ÷ 9 + (9-n) × G _b ÷ 9 B _b = n × B _a ÷ 9+ (9−n) × B _b ÷ 9 In the case of an image combined in this manner, the change in the image near the boundary becomes smooth, and a more natural image can be combined. Although this synthesizing process is shown as an example in the case of one neighborhood, it is possible to synthesize a smooth image near the boundary by expanding the area.

Next, FIG. 5 is a block diagram showing the configuration of an embodiment of the invention according to claim 3 of the present invention. The same functional blocks as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In the figure, 5 is an area calculation unit, which is a means for calculating the area of a closed region in which the background setting bit is 1. In the present embodiment, the background area is determined using the result obtained by the area calculation unit 5. Specifically, this process
This is done as follows. That is, in the image storage unit 1, 1 bit for work is allocated for area calculation. After the background setting process, all area calculation bits are set to 0, and step 1. The background setting bit of the corresponding pixel is 1,
If the area calculation bit is 0, proceed to step 2, otherwise proceed to the next pixel. When all the searches are completed, the processing ends. Step 2. Sets the coordinate value of the current pixel. Area value = 0. Step 3. Set the area calculation bit of the current pixel to 1. Added 1 to area value. Step 4. If there is a pixel having a background setting bit of 1 and an area calculation bit of 0 on the top, bottom, left and right, all the coordinate values of the corresponding pixel are stacked on the stack. Step 5. If there is contents in the stack, the coordinate value is extracted from the stack, and go to step 3, otherwise go to step 6. The coordinate value set in step 2 and the area value are output as a result, the processing is ended, each step processing of is performed, and the coordinate value of a certain background area,
Get its area. The area obtained here is a closed background area containing the coordinate values. This is performed for all pixels. For example, when the area having the maximum area is regarded as the background area as in the invention described in claim 4, the area calculation bit is set to 0 again to obtain the area. This processing is performed again using the coordinate values in accordance with the above processing procedure, and the area calculation bit is set to 1. Since the area where the bit is 1 is the background area having the largest area, the area calculation bit is transferred to the background setting bit, and the image composition section performs image composition by the above method. By performing such a process, it becomes possible to change the background area erroneously set inside the non-background area to the non-background area.

Next, FIG. 6 is a block diagram showing the configuration of an embodiment of the invention according to claim 5 of the present invention. The same functional blocks as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In the figure, reference numeral 6 denotes a threshold value setting unit that determines a threshold value related to the area of the background region obtained by the area calculation unit 5. Specifically, for example, when performing the process manually, the threshold value is input with a keyboard or the like. In case of automatic processing, 1. 1. Use 1% of the total area of the input image as the threshold, or 1 of the total area of the background area obtained by the area calculation unit 5
% As a threshold, or 3. A method such as using 1% of the area of the background area having the maximum area as the threshold value is conceivable. These are examples of automatic processing. Actually, the processing method and the threshold ratio are changed depending on the nature of the image to be processed. Even if the background area may be divided into the non-background areas by including the threshold setting unit 6 as described above, it is erroneous to consider the background area as the non-background area or the non-background area as the background area. It is possible to reduce detection.

In the case of the invention according to claim 6 of the present invention, by using both the value of lightness and hue in the background setting section, not only the background area can be set from a black and white image, but also in a color image. Even in the same hue, if the lightness is different, the background area and the non-background area can be separated from each other, so that the false detection can be reduced.

The present invention can be realized by software using a computer or by using a dedicated hardware circuit having each of these functions.

[0021]

As is apparent from the above description,
The image processing device of the present invention separates a certain image into a background region and a non-background region, and when synthesizing the non-background region with another image,
It is possible to extract the boundary between the non-background area and the background area and change it to the background area.Therefore, the effect of the background area included in the boundary area and the unnatural wavy shape can be avoided. It is possible to prevent this, and it is possible to combine images with less discomfort.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention according to claim 1.

FIG. 2 is an example of an image obtained by a background processing unit of a conventional image processing device.

FIG. 3 is an example of an image obtained by the boundary deleting unit of the above-described embodiment of the present invention.

FIG. 4 is a flow chart of processing of a boundary deletion unit of the above embodiment.

FIG. 5 is a configuration diagram showing an embodiment of the present invention according to claim 3;

FIG. 6 is a configuration diagram showing an embodiment of the present invention according to claim 5;

[Explanation of symbols]

 1 Image Storage Section 2 Background Setting Section 3 Boundary Deletion Section 4 Image Synthesis Section 5 Area Calculation Section 6 Threshold Setting Section 10 System Bus 11 CPU 12 Auxiliary Storage Device (HDD) 13 Scanner 14 Video Printer 20 A / D Converter 21 TV Camera 22 D / A converter 23 display

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04N 1/46 5/272 4226-5C H04N 1/46 Z (72) Inventor Masahiro Hamada Kadoma Osaka Prefecture 1006 Kadoma, Oita-shi Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. An image processing apparatus for clipping a non-background region of a given image, synthesizing the image with another image, and outputting the image.
An image storage unit that stores image data, a background setting unit that sets a background area, and in the set background area and non-background area, the boundary portion of the non-background area is scraped off based on a predetermined rule, and the background area is set. Boundary deletion part to be incorporated,
An image processing apparatus, comprising: an image combining unit that combines the obtained non-background area with the other image to generate a combined image. 2. The image processing apparatus according to claim 1, wherein the predetermined rule considers a state regarding a pixel in the vicinity of a pixel of interest. 3. An area calculation unit for calculating the area of the obtained background region, wherein in a plurality of obtained background regions, whether or not the region is a background is determined according to the calculated area of the background region. The image processing apparatus according to claim 1, wherein the image processing apparatus is an image processing apparatus. 4. The image processing apparatus according to claim 3, wherein only the area having the largest calculated area of the background area is processed as the background area. 5. A threshold setting unit for setting a threshold, wherein whether or not the region is the background is determined by the calculated area of the background region and the obtained threshold. 3. The image processing device according to item 3. 6. The image processing apparatus according to claim 1, wherein the background setting unit sets using both the brightness and the hue of the image.