JP2001169083A - Picture processing method, picture processor and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an appropriate line flare regardless of the shape of high light at the time of giving line flare to a picture including high light. SOLUTION: A reading means 1 reads picture data S0 and a picture processing means 2 extracts a high light pixel whose luminance becomes not less than a prescribed value in the picture displayed by picture data S0 and a high light area where the high light pixels are concentrated is extracted. The high light area is sorted to a circular high light area and the high light area of a shape except for the circle in accordance with a circular degree. Line flare data corresponding to the high light area is calculated. Calculated high light data is given to picture data S0, processed picture data S1 to which line flare is given is obtained and it is outputted from an output means 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image processing method and apparatus for applying striations to glitter contained in an image, and a computer-readable recording medium storing a program for causing a computer to execute the image processing method. It is.

[0002]

2. Description of the Related Art Digital image data obtained by a digital electronic still camera (hereinafter referred to as a digital camera) or digital image data obtained by reading an image recorded on a film can be converted into a hard copy such as a print or a display. An image processing system for reproducing as a soft copy has been proposed above. As described above, when reproducing digital image data, an image is output after performing various image processing such as gradation processing and color conversion processing on the image data.

By the way, when an image is recorded on a film by a camera, as a filter mounted on the camera and used, for example, a color correction filter, an ND filter, a polarization filter and the like are known. When photographing is performed, a cross filter for causing one or a plurality of striations to appear radially on the image, centering on the luminosity which is a high luminance portion in the image, is also used. For example, as shown in FIG.
When the scene including the image is photographed without using the cross filter, an image containing no striation is obtained. However, when the image is photographed using the cross filter, as shown in FIG.
The streaks appear radially in the high-brightness portion in the image, such as the window light and the outside light 11.

On the other hand, the cross filter is not always used at the time of photographing, and is mounted on the camera by the photographer only when it is desired to obtain the effect of the cross filter.
Images taken without using a cross filter do not include striations. On the other hand, there is also a demand for providing a streak to an image that does not include such streaks. For this reason,
There has been proposed a method of applying a streak to glitter contained in an image by image processing. This method extracts a bright pixel whose luminance in an image is equal to or more than a predetermined value, and imparts a streak to each extracted bright pixel, whereby a cross filter is used without using a cross filter. In the same manner as in the case where photographing is performed using, it is possible to obtain an image in which striations are added to the glitter.

[0005]

By the way, as described above, in the method of applying striations, for example, bright pixels are concentrated to some extent to form a circular bright region, such as a car headlight or an outside light. In this case, the streak is applied to each pixel in the circular bright region, so that the streaks overlap each other, and the streaks appearing in the external light become round as shown in FIG. Would. For this reason, a bright pixel is extracted in the image, and a circular bright area in which the bright pixels are concentrated to form a circular shape is further extracted,
A method has been proposed in which a streak corresponding to the shape is provided to the circular bright region (Japanese Patent Application No. 10-8 / 1998).
No. 9893).

[0006] However, Japanese Patent Application No. Hei 10-8989 discloses this patent application.
According to the method of No. 3, an appropriate streak can be given to the circular shining area as shown in FIG. 11, but the shining is concentrated like a water surface with waves or a window light of a building. However, if the shape is not circular, or if the bright pixels are not so concentrated, no streak appears in the bright (see FIG. 11). For this reason, the amount of striations on the image is reduced, resulting in an unnatural image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and records an image processing method and apparatus capable of appropriately applying striations to an image and a program for causing a computer to execute the image processing method. It is an object of the present invention to provide a computer-readable recording medium.

[0008]

An image processing method according to the present invention extracts, based on image data, bright pixels in an image represented by the image data, and highlights a region where the bright pixels are concentrated. A first region representing a streak extending from the circular brilliant region according to the shape of the circular brilliant region, extracting the brilliant region into a circular brilliant region and a non-circular brilliant region according to the degree of circularity. And second light data representing light extending from each of the bright pixels in the non-circular bright area and the bright pixels other than the bright area, and generating the first and second light. It is characterized in that processed image data is obtained by synthesizing the line data and the image data.

[0009] Here, "extracting bright pixels in an image"
This means that the luminance may be obtained from, for example, R, G, B data constituting the image data, and a pixel having the luminance equal to or higher than a predetermined threshold value may be extracted as a bright pixel.

The "first and second striation data" includes data representing a plurality of striations extending radially from the glittering region and striations extending from the glittering region and including a polygonal high-luminance region. Can be used.

Further, the generation of the first and second striation data may be performed before the generation of any striation data.
The generation of the first and second striation data may be performed simultaneously.

[0012] An image processing apparatus according to the present invention includes a brilliant pixel extracting means for extracting a brilliant pixel in an image represented by the image data, based on the image data, and a brilliant area where the brilliant pixels are concentrated. A glittering area extracting means for extracting the glittering area, a sorting means for sorting the glittering area into a circular glittering area and a non-circular glittering area according to the degree of circularity, and the circular glittering area according to the shape of the circular glittering area. First streak data generating means for generating first streak data representing an extending streak; and second streak indicating a streak extending from each of the bright pixels in the non-circular bright region and the bright pixels other than the bright region. Second streak data generating means for generating streak data, and synthesizing means for synthesizing the first and second streak data with the image data to obtain processed image data. Features A.

In the image processing apparatus according to the present invention, the first striation data generating means and the second striation data generating means may be shared.

[0014] A computer-readable recording medium may be provided as a program for causing a computer to execute the image processing method according to the present invention.

[0015]

According to the present invention, with respect to the circular luminous region obtained by the sorting, the luminous streak is given by the first luminous line data representing the luminous line extending from the circular luminous region according to the shape. For the bright pixels other than the non-circular bright region and the bright region, the second stripe representing the bright line extending from each bright pixel in the non-circular region and the bright pixel other than the bright region.
The striations are given by the striation data. For this reason, it is possible to appropriately apply a streak to the circular bright region in the image so that the streak is not rounded. In addition, since streaks can be given to non-circular bright areas such as window lights of buildings and waves on the water surface and portions where bright pixels are not so concentrated, the amount of streaks in an image is reduced. Thus, an image free from unnaturalness can be obtained. Therefore, similarly to the case where the photographing is performed using the cross filter, it is possible to obtain an image in which the glitter in the image is appropriately provided with the streak.

[0016]

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

FIG. 1 is a schematic block diagram showing the configuration of an image processing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the image processing apparatus according to the present embodiment includes an MO, a CD-R
Reading means 1 for reading image data S0 recorded on a recording medium such as
An image processing means 2 for performing a process of imparting striations to the image data S0 to obtain processed image data S1, a printer and a monitor for reproducing the processed image represented by the processed image data S1 And other output means 3.

The image data S0 may be obtained by photographing a subject with a digital camera, or by photoelectrically reading an image recorded on a film by a reading means such as a scanner. May be used.

The image processing means 2 performs image processing for adding a streak to the radiance in the image as described later, and performs other image processing such as gradation processing and color conversion processing as necessary. Also performs processing.

Next, the operation of this embodiment will be described. FIG. 2 is a flowchart showing the operation of the present embodiment. First, the image data S0 is read by the reading means 1 and input to the image processing means 2 (step S1). In the present embodiment, as shown in FIG. 3, the image data S <b> 0 represents an image including the building 10 and the outside light 11 illuminated by window lights. Next, based on the image data S0, the luminance of each pixel of the image represented by the image data S0 is calculated (step S2). Here, the luminance is Y, and the color data constituting the image data S0 are R0, G
Assuming 0 and B0, the luminance Y is calculated by, for example, the following equation (1).

Y = 0.299R0 + 0.587G0 + 0.114B0 (1) Note that the average density of the color data R0, G0, and B0 may be used instead of the luminance Y.

After calculating the luminance Y in this way, a bright pixel whose luminance Y is equal to or more than a predetermined threshold Th1 is extracted (step S3). Next, a region where many bright pixels are concentrated, that is, a region where many bright pixels are adjacent or close to each other is extracted as a bright region K (step S4). FIG. 4 is a diagram showing the extracted bright region K. As shown in FIG. 4, the window light portion of the building 10 and the light portion of the outside light 11 are extracted as the bright region K by the processing in step S4.

Next, the bright region K is selected according to the circularity of the region (step S5). This selection is performed based on, for example, the complexity e of the shape of the bright region K. here,
The complexity e can be expressed by the following equation (2). The complexity e is minimum when the shape of the bright region K is circular, and increases as the shape becomes more complicated.

E = (perimeter of the glittering area K) ² / (area of the glittering area) (2) The complexity e obtained in this way is determined by a predetermined threshold Th2.
The bright region K is sorted into a circular bright region K1 whose complexity e is less than the threshold Th2 and a non-circular bright region K2 whose complexity e is equal to or greater than the threshold Th2. Here, the value of the complexity e is relatively small because the bright region K in the lighting of the outside light 11 is substantially circular, but the complexity is small because the bright region K in the window light of the building 10 is substantially rectangular. The value of e is relatively large. Therefore, the bright region K of the light of the outside light 11 is selected as a circular bright region K1 as shown in FIG. 5, and the bright region K of the window light of the building 10 is selected as a non-circular bright region K2 as shown in FIG.

Then, the first streak representing the striation to be given to the circular bright region K1 obtained by the sorting in step S5.
Is calculated (step S6). On the other hand, regarding the non-circular bright region K2, the non-circular bright region K2
The second striation data representing the striations to be given to is calculated (step S7). The striations represented by the second striation data are not only striations in the non-circular bright region K2, but also
It also includes striations to be given to the brilliant pixels that are not extracted as the brilliant region K in the process of step S4.

The first striation data is calculated based on the average luminance, color, and size of the circular bright region K1 based on the shape, length, thickness, color, number, and intersection of the striations. This is performed by determining the angle, the degree of disappearance, and the like. Here, as the average luminance of the glittering area, a value obtained by dividing the added value of the luminance in the circular glittering area K1 by the number of pixels can be used. As the color, for example, R, G, and R in the circular glittering area K1 can be used. The difference or ratio of the average density for each B can be used, and the size of the circular bright region K1 can be, for example, the number of pixels in the circular bright region K1.

FIGS. 7A and 7B show the shapes of the striations.
As shown in FIG. 7C, a plurality of striations extending radially from the circular bright region K1 or a circular bright region K1 as shown in FIG.
Can be set by previously selecting a desired shape from a plurality of types of streaks, such as a streak including a polygonal high-brightness region extending from.

The length of the striations can be determined, for example, so as to increase as the luminance of the circular luminous region K1 increases and to increase as the size of the circular luminous region K1 increases. In addition, the appearance of the processed image can be improved by obtaining the density of the entire image represented by the image data S0 and reducing the length of the striation as the density is lower.

The thickness of the streak can be determined, for example, such that the thickness increases as the luminance of the circular luminous region K1 increases and increases as the size of the circular luminous region K1 increases.

The color of the striations can be determined, for example, so as to match the color of the image represented by the image data S0. In addition, a portion close to the circular brilliant region K1 on the streak is made to match the color of the circular brilliant region K1 on the image represented by the image data S0,
For a portion distant from the circular bright region K1, the color may periodically change (hue rotates) according to the distance from the circular bright region K1.

For example, a predetermined angle can be set as the intersection angle of the striations. Alternatively, a face area corresponding to a person's face exists in the image represented by the image data S0. It is determined whether or not the striation is performed, and if the face region exists, the angle of the striation may be automatically set so that the striation to be applied does not overlap the face region.

The degree of disappearance of striations means that the striations are circular bright regions K
The luminance decreases as the distance from 1 decreases, and is a numerical value representing the degree of the decrease. Here, the extinction degree is x, the pixel value of the image represented by the image data S0 is p, and the luminous area K1,
Assuming that the pixel value of K2 is q, the pixel value L of the striation data can be expressed by the following equation (3).

L = x × q + (1−x) × p (3) where 0 ≦ x ≦ 1 On the other hand, for the second striation data, the non-circular bright region K
2 based on the brightness and color of the brilliant pixels other than the brilliant region K and the shape and length of the striations as in the first striation data.
The determination is performed by determining the thickness, color, number, crossing angle of striations, degree of disappearance, and the like. At this time, the shape of the striations may be the same as the first striation data, but may be different.
The streak represented by the second streak data is provided for each pixel in the non-circular brilliant region K2 and the brilliant region K.

When the first and second striation data are calculated in this manner, the striations on the image represented by the image data S0 are calculated based on the first and second striation data. Is rewritten to obtain the processed image data S0 (step S8), which is output by the output means 3 (step S9), and the processing is terminated. FIG. 8 is a diagram showing a processed image represented by the processed image data S0. As shown in FIG. 8, the processed image obtained in the present embodiment is such that the streak does not become round even if the bright region K is circular like the light of the outside lamp 11, and further, the window of the building 10 Lights are also appropriately provided with striations.

In the above embodiment, the first and second striation data are calculated, and striations are simultaneously applied to both the bright regions K1 and K2 based on the striation data. However, it is also possible to first apply a streak to the circular bright region K1, and then to apply a streak to the non-circular bright region K2 and the bright pixels other than the bright region K in accordance with the condition of the striation. First, after applying striations to the pixels other than the non-circular bright region K2 and the bright region K, the circular bright region K
Light striations may be added to 1.

In the above embodiment, the shape of the striation is determined as shown in FIG. 7, but the shape is not limited to this. For example, the number of striations is three or five or more. A striation shape may be used.

Further, in the above embodiment, the case where the image processing apparatus according to the present invention is used alone has been described. You may make it give.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating a configuration of an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment;

FIG. 3 is a diagram showing an image represented by image data S0.

FIG. 4 is a diagram showing an extracted bright region.

FIG. 5 is a diagram showing a bright region K1 obtained by sorting.

FIG. 6 is a diagram showing a bright region K2 obtained by sorting.

FIG. 7 is a view showing the shape of a striation.

FIG. 8 is a diagram showing a processed image.

FIG. 9 is a diagram showing an image obtained by performing photographing using a cross filter.

FIG. 10 is a view showing an image to which striations are added in conventional image processing (part 1);

FIG. 11 is a diagram showing an image to which striations are added in conventional image processing (part 2);

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Readout means 2 Image processing means 3 Output means 10 Building 11 Outside light

Claims (3)

[Claims] 1. A method for extracting a bright pixel in an image represented by the image data based on the image data, extracting a region where the bright pixels are concentrated as a bright region, and Selecting a circular luminous region and a non-circular luminous region according to the degree, and generating first vein data representing a vein extending from the circular luminous region according to the shape of the circular luminous region; Generating second streak data representing streaks extending from each of the bright pixels in the area and the bright pixels other than the bright area, and combining and processing the first and second streak data and the image data; An image processing method characterized by obtaining completed image data. 2. A brilliant pixel extracting means for extracting a brilliant pixel in an image represented by the image data based on the image data, and a brilliant area extracting unit for extracting an area where the brilliant pixels are concentrated as a brilliant area. Means, a sorting means for sorting the glittering region into a circular glittering region and a non-circular glittering region according to the degree of circularity, and a stripe representing a stripe extending from the circular glittering region according to the shape of the circular glittering region. First streak data generating means for generating one streak data; and second streak data representing streaks extending from each of the bright pixels in the non-circular bright area and the bright pixels other than the bright area. An image processing apparatus comprising: a second striation data generating unit that performs processing; and a synthesizing unit that combines the first and second striation data and the image data to obtain processed image data. . 3. A procedure for extracting a bright pixel in an image represented by the image data based on the image data, a procedure for extracting an area where the bright pixels are concentrated as a bright area, And selecting a circular luminous region and a non-circular luminous region according to the degree of circularity, and generating the first luminous line data representing the luminous line extending from the circular luminous region according to the shape of the circular luminous region. Generating second streak data representing streaks extending from each of the bright pixels in the non-circular bright area and the bright pixels other than the bright area; and the first and second striation data. And a computer-readable recording medium storing a program for causing a computer to execute an image processing method, comprising: combining the image data with the image data to obtain processed image data.