JP4935665B2 - Imaging apparatus and image effect providing program - Google Patents

Description

  The present invention relates to an imaging apparatus that applies an image effect to a captured image, and an image effect applying program.

  Conventionally, for example, a cross filter is attached to a lens of a digital camera to capture an image, or an image effect is applied to an image obtained by imaging, and an image with an image effect is generally obtained. Yes.

For example, when an image effect is applied to an image obtained by imaging (hereinafter referred to as an original image), if the image effect is directly applied to the original image, it takes time to apply the image effect. An image to be used as an image effect (hereinafter referred to as a mask image) is created from the reduced image obtained by reducing the image, and the created mask image is enlarged so as to have the same angle of view as the original image, and then combined with the original image. (See Patent Document 1).
JP 2006-213121 A

  However, since the mask image is enlarged when it is combined with the original image, the image quality of the mask image is degraded. That is, when a mask image with reduced image quality is directly combined with the original image, the boundary between the pattern formed on the mask image and the original image is easy to understand, and the applied image effect tends to be unnatural.

  The present invention has been invented to solve the above-described problems, and can provide an appropriate image effect to an original image even when a mask image is created from a reduced image. It is an object of the present invention to provide an imaging device and an image effect imparting program.

  An image pickup apparatus according to a first aspect of the present invention is an image reduction means for reducing an original image obtained at the time of image pickup, and an image effect mask to be applied to the original image using the reduced image generated by the image reduction means. Image generating means for generating an image; filter processing means for executing a filtering process on the mask image; image enlarging means for enlarging the filtered mask image; the enlarged mask image and the original image; And image synthesizing means for synthesizing.

  According to a second aspect of the present invention, in the first aspect of the present invention, the image processing device includes a region detection unit that detects a region of interest in the reduced image, and the image generation unit creates a mask image corresponding to the detected region of interest. And

  In a third aspect based on the second aspect, the area detection means calculates a luminance at each pixel of the reduced image, and a pixel having a higher luminance among the calculated luminances at each pixel is used as the attention area. It is characterized by detecting.

  According to a fourth aspect, in the second or third aspect, the apparatus further comprises color information acquisition means for acquiring color information at the periphery of the attention area detected by the area detection means, wherein the image generation means The mask image is generated based on the size of the region and the color information at the periphery of the region of interest.

  In a fifth aspect based on any one of the second to fourth aspects, the image generation means selects and selects one of the attention areas from the plurality of attention areas when a plurality of the attention areas are detected. A mask image based on the attention area thus generated is generated.

  According to a sixth invention, in any one of the first to fifth inventions, the mask image is an image having the same image size as the reduced image and a preset pattern formed at a position corresponding to the region of interest. It is characterized by comprising.

  According to a seventh invention, in the sixth invention, the pattern has a shape in which a plurality of lines are radially extended from the region of interest as a base point.

  According to an eighth aspect, in the seventh aspect, the color of the pixel at the tip periphery of each of the plurality of lines is changed in a stepwise manner so that the color of the line approaches the background color of the mask image. It is characterized by.

  According to a ninth aspect of the invention, there is provided an image effect imparting program for obtaining a reduced image by reducing an original image obtained at the time of imaging, and an image effect imparted to the original image using the reduced image. Generating a mask image; performing a filtering process on the generated mask image; enlarging the mask image subjected to the filtering process; and combining the enlarged mask image and the original image. And causing the computer to execute.

  According to the present invention, after the generated mask image is filtered, the image is enlarged so as to have the same angle of view as the original image, so that the image quality of the enlarged mask image is prevented from becoming rough. In addition, since the mask image and the original image are combined, there is no sense of incongruity with the applied image effect.

  FIG. 1 is a schematic diagram illustrating an example of the configuration of the digital camera 10. The digital camera 10 is centrally controlled by the CPU 15. Since the operation signals of the operation unit 16 and the release button 17 are input to the CPU 15, the CPU 15 controls each unit of the digital camera 10 based on the input operation signals.

  The imaging optical system 20 includes a zoom lens 22 and a focus lens 23 in addition to the imaging lens 21. The zoom lens 22 is moved along the optical axis direction by the lens driving mechanism 24 when changing the imaging magnification at the time of imaging. The focus lens 23 is finely moved in the optical axis direction by the lens driving mechanism 24 when performing focus adjustment during imaging.

  The CCD 25 receives subject light incident via the imaging optical system 20, and photoelectrically converts the subject light by accumulating signal charges corresponding to the received light amount. The accumulation of signal charges in the CCD 25 and the output of the accumulated signal charges are controlled by the driver 26.

  The signal charge accumulated by the CCD 25 is output to the AFE circuit 27 as an analog image signal. The AFE circuit 27 includes an AGC circuit and a CDS circuit (not shown). The AFE circuit 27 performs analog processing such as gain control and noise removal on the input analog image signal.

  The DFE circuit 28 converts the analog image signal subjected to the analog processing by the AFE circuit 27 into a digital image signal. The converted digital image signals are collected frame by frame and stored in the buffer memory 30 as digital image data. The driver 26, the AFE circuit 27, and the DFE circuit 28 are controlled based on the operation timing in the timing generator (TG) 31, respectively. Reference numeral 32 denotes a bus, and each part of the digital camera 10 is electrically connected via the bus 32.

  The image processing unit 35 performs image processing such as contour compensation, gamma correction, and white balance adjustment on the digital image data stored in the buffer memory 30. The digital image data subjected to this image processing is subjected to format processing (image post-processing) for compression by a storage method such as the JPEG method, and then stored in the buffer memory 30 again. The digital image data stored in the buffer memory 30 is compressed using a compression rate corresponding to a predetermined compression method.

  For example, when a through image is displayed on the LCD monitor 36 provided in the digital camera 10, compression processing is executed on the digital image data after the image processing using a compression rate that matches the resolution of the LCD monitor 36. And output to the display control unit 37.

  On the other hand, when storing digital image data, a compression process using a compression rate suitable for image storage is performed and stored in the built-in memory 38. The digital image data stored in the built-in memory 38 is written into a storage medium 40 such as a memory card or an optical disk via the media controller 39. As the compression rate for image storage, in addition to the compression rate set for the image storage resolution set in advance in the digital camera 10, the compression rate is set according to the resolution set by the user operating the operation unit 16 in advance. Compression rate.

  The strobe device 41 emits strobe light toward the subject when, for example, the luminance of the subject in the photometric sensor 43 is a predetermined value or less. The strobe light emission timing and amount of light emitted from the strobe device 41 are controlled by a strobe control unit 42.

  In the following description, image data before reduction processing is referred to as original image data, image data after reduction processing is referred to as reduction image data, and image data for image decoration created based on the reduction image data is referred to as mask image data. To do. Further, the display of original image data, reduced image data, and mask image data will be referred to as an original image, a reduced image, and a mask image, respectively.

  In addition to reducing the original image data stored in the built-in memory 38 at a predetermined reduction rate, the image enlargement / reduction unit 50 enlarges mask image data described later at a predetermined enlargement rate. In order to increase the processing speed when creating mask image data, which will be described later, the reduction ratio described above may be increased. However, the enlargement ratio when the mask image is enlarged also increases. The image quality of the enlarged mask image is degraded. Therefore, the reduction rate of the original image data when creating the mask image data is set in consideration of the processing speed and the image quality of the mask image. On the other hand, the enlargement ratio is an enlargement ratio at which the size of the mask image is the same as the size of the original image. As a method for reducing and enlarging the image data, a known bilinear method and a bicubic method can be cited.

  The image generation unit 51 generates mask image data to be combined with the original image data. The image generation unit 51 creates mask image data from the size (number of pixels) of the attention area detected by the area detection unit 52 described later and the color information acquired by the color information acquisition unit 53 described later. .

  As shown in FIG. 2, when the mask image data is displayed on the LCD monitor 36, a mask image MI having the same angle of view as the reduced image is displayed. This mask image MI is made up of an image in which, for example, cross patterns 66 and 67 with high luminance are arranged on a black background (hatched area 65 indicated by a dot in FIG. 2). The cross pattern described above has a shape in which a plurality of lines starting from a pixel that becomes the center of a region of interest described later are radially extended. The length and thickness of the cross pattern line are determined based on the size (number of pixels) of the region of interest. Note that table data in which the thickness and length of the cross pattern correspond to the size of the attention area is stored in advance, and the size and thickness of the cross pattern may be determined from the extracted size of the attention area.

  The color of the cross pattern is determined based on the color information acquired by the color information acquisition unit 53 described later. That is, the gradation value (RGB value or YCrCb value) of each pixel is determined so that the luminance decreases from the center side of the cross pattern toward the tip of each line. Note that the number of lines in the cross pattern and the angle of the lines described above may be arbitrarily selected by the user in advance or may be set in advance. The cross pattern may be arranged for all detected attention areas, or the attention area where the cross pattern is arranged may be selected depending on the size of the attention area.

  The image generation unit 51 includes an area detection unit 52 and a color information acquisition unit 53. The region detection unit 52 detects a region of interest in the reduced image. As the detection of the attention area, pixels with high luminance are extracted from the reduced image, and among the extracted pixels, an area adjacent so that a plurality of pixels are substantially circular or substantially elliptical is defined as the attention area. To do. When the attention area is detected, a pixel that is the center of the attention area is also obtained.

  FIG. 3A illustrates an image PI obtained by capturing a night view around a station, for example. When a night scene is imaged, the farther away from the light emitting part of the outer light, the lower the luminance because the influence of the irradiation light from the light emitting part of the outer light becomes lower. As shown in FIG. 3B, in the image PI, for example, when attention is paid to the light emitting portion of the outdoor lamp and the peripheral region 70 thereof, the region corresponding to the light emitting portion of the external light (region 71 where hatching is not performed) and the peripheral edge thereof. The brightness decreases in the order of the area (hatched area 72 where hatching is performed) and the outer area (area 73 where dot hatching is performed). That is, since the luminance in the pixels of the region 71 is higher than the luminance detected as the attention region, the region 71 is detected as the attention region. In this case, the pixel 74 is the center of the attention area 71.

  The color information acquisition unit 53 acquires, as color information, an average value of gradation values of pixels having substantially the same luminance among the peripheral pixels of the region of interest detected by the region detection unit 52. In FIG. 3B, since the area 72 is an area where the influence of the irradiation light is large due to the lighting of the outside lamp, the average value of the gradation values of each pixel which is an area where the influence of the irradiation light is large. Is acquired as color information.

  The filter processing unit 54 performs low-pass filter (LPF) processing on the generated mask image data. In this LPF process, among the 9 pixels 71 to 79 in total of 3 × 3, the weight for the pixel 75 at the center is “2”, and the weight for the pixels 71 to 74 and the pixels 76 to 79 is “1”. A process for performing the convolution calculation. As shown in FIG. 4, for example, a total of nine pixels 71 to 79 of 3 × 3 are described. The pixel 77 is red, the pixels 74 and 78 are pink, the pixels 71 to 73, the pixels 75 and 76, and the pixel 79 are In the case of white, the pixel 75 changes from white to light pink by performing this LPF process. Since this processing is performed using all the pixels that make up the mask image, an image with a clear boundary between the pattern and the background in the mask image is processed into an image with a blurred boundary between the pattern and the background. Can do.

  The image composition unit 55 synthesizes the mask image data generated by the image generation unit 51 and the reduced image data, or synthesizes the mask image data enlarged by the image enlargement / reduction unit 50 and the original image data. The image data synthesized by the image synthesis unit 55 is stored in the built-in memory 38.

  Next, a processing procedure for giving an image effect to image data captured by the digital camera 10 will be described based on a flowchart of FIG. It should be noted that it may be possible for the user to select in advance whether or not to apply an image effect to the captured image data, or an image effect may be automatically applied to all image data. When the imaging process is executed by the digital camera 10, the image data acquired by imaging is used as original image data, and the process proceeds to step S <b> 101.

  Step S101 is processing for creating reduced image data from original image data. Note that reduced image data is created separately from the original image data and stored in the built-in memory 38 by the processing in step S101.

  Step S102 is processing for detecting a region of interest using the reduced image data created in step S101. In step S102, pixels having high luminance are extracted from the pixels constituting the reduced image, and the adjacent areas are selected as the attention area so that the plurality of extracted pixels are substantially circular or oval. To detect. At the time of detecting this attention area, the pixel serving as the center is specified. That is, in the case of FIG. 3, in the case of an image obtained by imaging the vicinity of the station at night, the light emitting part of the outdoor lamp is detected as the attention area.

  Step S103 is processing for detecting color information of pixels at the periphery of the attention area extracted in step S102. In step S103, pixels having substantially the same luminance are detected from the peripheral area of the attention area, and a value obtained by averaging the gradation values of the detected pixels is acquired as color information.

  Step S104 is a process for creating mask image data. Since the size (number of pixels) of the attention area extracted in step S102 is known, the size of the pattern arranged in the mask image, that is, the length of each line of the cross pattern is determined from the size of the attention area. The number of pixels indicating the thickness and the number of pixels indicating the thickness are respectively determined. Also, using the acquired color information, the color (RGB value or YCrCb value) of each pixel of the cross pattern is determined so that the luminance decreases from the base point of the cross pattern toward the tip of each line. By these determinations, mask image data having a black background and a cross pattern with a pixel corresponding to the center of the region of interest as a base point is generated.

  Step S105 is an LPF process for the mask image data created in step S104. By performing this LPF process, the mask image becomes an image in which the boundary between the cross pattern and the background is blurred.

  Step 106 is a process of combining the reduced image data and the mask image data. As shown in FIG. 6, in the case where the acquired image is, for example, an image PI obtained by capturing a night view around the station and the created mask image MI, the image CI is acquired by combining these images.

  Step S107 is a process of displaying the image obtained by executing the process of step S106 on the LCD monitor 36.

  Step S108 is processing for selecting whether or not to change the synthesized image. For example, if the synthesized image is not changed, the process proceeds to step S109. If the synthesized image is changed, the process returns to step S102. Note that changing the combined image means, for example, changing the pattern of the mask image to be combined from a cross pattern to another pattern, or if the selected pattern is a cross pattern, the number of lines in the cross pattern In addition, the pattern of the mask image data is not changed, but the angle of the cross pattern is changed.

  Step S109 is processing for enlarging the mask image data. By performing the processing in step 105, the mask image data is an image in which the boundary between the background and the cross pattern is blurred. Therefore, even if the mask image data is enlarged in step S109, the image quality of the mask image data is deteriorated. You do n’t have to.

  Step S110 is a process of combining the original image data and the enlarged mask image data. Since the image quality of the mask image data enlarged in step S109 has not deteriorated, it does not give a sense of incongruity to the cross pattern synthesized with the original image. Thereby, an image equivalent to an image obtained by performing imaging using a cross screen filter can be created in a pseudo and high speed manner. Step S <b> 111 is processing for storing the created composite image data in the built-in memory 38.

  In this embodiment, the reduced image and the mask image are combined and then displayed on the LCD monitor 36. However, the present invention is not limited to this, and the combined image of the original image and the enlarged mask image is reduced. It may be displayed on the LCD monitor 36.

  In the present embodiment, a reduced image obtained by reducing the original image is used. However, for example, if the digital camera is capable of displaying a thumbnail image on the LCD monitor 36, the thumbnail image can be used as the reduced image.

  In the present embodiment, the image enlargement / reduction unit 50, the image generation unit 51, the filter processing unit 54, and the image synthesis unit 55 are configured separately from the image processing unit 35 and the CPU 15, but are not limited thereto. The image processing unit 35 or the CPU 15 may have the functions of these units.

  In the present embodiment, a cross pattern is cited as a mask image pattern, but the present invention is not limited to this. For example, a pattern such as a note or a heart may be used.

  Note that the cross pattern described above is generally formed so that the width (thickness) of the line becomes narrower toward the tip. That is, as shown in FIG. 7, when the tip of a line is narrowed, for example, when the number of pixels corresponding to the width of the line is five, the number of pixels is gradually reduced to three pixels and one pixel toward the tip. ing. When LPF processing is performed in the case of such a line, for example, the image quality is improved at the periphery of the pixel whose width is reduced (in FIG. 7, the pixel in the A row and the third column and the pixel in the B row and the seventh column). In some cases, it is not possible to prevent a decrease in the width of the cross pattern, or each line of the cross pattern becomes thinner than the intended thickness. In order to prevent such deterioration of image quality and thinning of the line itself, for example, among the pixels at the end of the line, the color of the pixel at the edge of the line is not the background color, and the line color and the background color It is conceivable to use a color having an intermediate gradation value.

  For example, the pixel in row A will be described. In this row A, the pixels used as a line are up to the pixel in the second column. Is divided by the number of pixels in the 3rd to 10th columns that are not used as lines (in this case, 8). The value obtained by the division is subtracted from the gradation value of the pixel in the second column, and the gradation value obtained by the subtraction is set as the gradation value in the pixel in the A row and the third column. A gradation value obtained by subtracting the value obtained by the above-described division from the gradation value of the pixel in the third column is set as the gradation value in the pixel in the A row and the fourth column. Similarly, by obtaining the gradation values of the pixels in the fifth to tenth columns, the colors of the pixels in the third to tenth columns that are not used as lines gradually approach the background color, that is, as lines. The shades of pixels in the 3rd to 10th columns are determined. The same applies to the E row.

  The same applies to the B row and the D row, but in the B row and the D row, the pixels that are not used as lines are the pixels in the seventh to tenth columns. The difference is divided by the number of pixels (in this case, 4), and the gradation value of the pixel corresponding to each column may be obtained. In this way, the image quality degradation that occurs when low-pass filter processing is performed by determining the color of each pixel so that each of the pixels at the tip of the line gradually approaches the background color toward the tip of the line Can be suppressed.

  When the above-described method is used, when the line width is large (the number of pixels corresponding to the line width is increased), the line is configured so that the line color approaches the background color toward the tip. The color of the pixel will be determined. For example, the color of the pixel in the outer row is darker than the color of the pixel in the inner row, that is, the color in the pixel in one row and the pixel in another row The shade of the image may be reversed. In such a case, without using all the pixels in the outer row, that is, without using all the pixels from the pixels adjacent to the pixels constituting the line to the pixels at the tip of the line, for example, the width of the line For a predetermined number of pixels, such as pixels from a pixel that becomes thinner to a pixel that the width of the next line becomes thinner, the color of each pixel may be determined so as to gradually approach the background color.

  In the present embodiment, an area with high luminance is detected as an attention area, and a cross pattern is synthesized with the detected attention area. For example, the background color information of the original image or the reduced image and the attention area It is also possible to acquire the color information and to add a cross pattern to the region of interest consisting of the same color information as the background color information. In addition, it is also possible to acquire background color information and adjust the color of the pattern of the mask image data to be synthesized in accordance with the acquired background color information.

  In the present embodiment, a digital camera having a function of adding an image effect to a captured image has been described. However, the present invention is not limited to this. For example, image processing that can execute the procedure shown in the flowchart of FIG. It may be a device. Moreover, the program which can make a computer perform the procedure shown in the flowchart of FIG. 5 and the storage medium which memorize | stores this program and can be read with a computer may be sufficient.

It is a functional block which shows an example of the outline of a digital camera. It is a figure which shows an example of a mask image. It is a figure which shows an example of the image obtained when the periphery of a station at night is imaged. It is a figure which shows an example of a low-pass filter process. It is a flowchart which shows the process sequence which provides an image effect. It is a figure which shows an example of the image to which the image effect was provided. It is a figure which shows an example of the color scheme of the pixel of the line tip of a cross pattern.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Digital camera, 38 ... Built-in memory, 50 ... Image expansion / contraction part, 51 ... Image generation part, 52 ... Area | region detection part, 53 ... Color information acquisition part, 54 ... Filter processing part, 55 ... Image composition part, 66, 67 ... Cross pattern

Claims (9)

Image reduction means for reducing the original image obtained at the time of imaging;
Image generation means for generating a mask image for image effect to be applied to the original image using the reduced image generated by the image reduction means;
Filter processing means for performing filter processing on the mask image;
Image enlarging means for enlarging the filtered mask image;
Image synthesizing means for synthesizing the enlarged mask image and the original image;
An imaging apparatus comprising: The imaging device according to claim 1,
Comprising an area detecting means for detecting an attention area in the reduced image;
The imaging apparatus, wherein the image generation means creates a mask image corresponding to the detected attention area. The imaging apparatus according to claim 2, wherein
The imaging apparatus according to claim 1, wherein the area detecting unit calculates a luminance at each pixel of the reduced image, and detects a pixel having a higher luminance among the calculated luminances at each pixel as the attention area. In the imaging device according to claim 2 or 3,
Color information acquisition means for acquiring color information at the periphery of the region of interest detected by the area detection means;
The imaging apparatus, wherein the image generation unit generates the mask image based on a size of the attention area and color information at a periphery of the attention area. In the imaging device according to any one of claims 2 to 4,
The image generation means selects one of the attention areas from the plurality of attention areas when a plurality of the attention areas are detected, and generates a mask image based on the selected attention areas. Imaging device. In the imaging device according to any one of claims 1 to 5,
The imaging apparatus according to claim 1, wherein the mask image is an image having the same image size as the reduced image, and a preset pattern formed at a position corresponding to the region of interest. The imaging device according to claim 6,
The image pickup apparatus according to claim 1, wherein the pattern has a shape in which a plurality of lines are radially extended with the center of the region of interest as a base point. The imaging apparatus according to claim 7,
An image pickup apparatus, wherein a color of a pixel at a peripheral edge of each of the plurality of lines is changed stepwise from a color of the line so as to approach a background color of the mask image. Obtaining a reduced image by reducing the original image obtained at the time of imaging;
Using the reduced image to generate a mask image for an image effect to be applied to the original image;
Performing a filtering process on the generated mask image;
Enlarging the filtered mask image;
Combining the enlarged mask image and the original image;
An image effect providing program that causes a computer to execute the above.

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