Image processing apparatus, method and program
First Claim
1. An image processing apparatus comprising:
- a correction amount calculation means for calculating a correction amount to be added to each pixel of an image to compress a dynamic range of the image by referring to a compression table that defines a relationship between the density of each pixel of the image and the compression amount for compressing the dynamic range of the image;
a processing means for obtaining a processed image of which the dynamic range has been compressed by performing processing for compressing the dynamic range of the image by adding the correction amount to each pixel of the image; and
a judgment means for judging whether an estimated change amount of the image by the processing for compressing the dynamic range, the estimated change amount being obtained from the compression table, is larger than a predetermined threshold value, wherein if the judgment is YES, the correction amount calculation means produces an unsharp image of the image and calculates the correction amount by using the unsharp image and by referring to the compression table, or if the judgment is NO, the correction amount calculation means calculates the correction amount by using the image instead of the unsharp image and by referring to the compression table.
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Accused Products
Abstract
An image analysis unit analyzes an image on which AE processing has been performed and obtains a coefficient for obtaining a gradient of a compression table for compressing a dynamic range of the image. A compression table creation unit creates a compression table. A correction amount calculation unit judges whether the gradient of the compression table is larger than a predetermined threshold value. If the judgment is YES, loss of fine texture in the image by dynamic range compression is significant. Therefore, the correction amount calculation unit calculates a correction amount by using an unsharp image of the image. If the judgment is NO, loss of fine texture in the image is insignificant, the correction amount calculation unit calculates the correction amount by using the image. A compression processing unit compresses the dynamic range of the image by the correction amount and obtains a processed image data set.
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Citations
12 Claims
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1. An image processing apparatus comprising:
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a correction amount calculation means for calculating a correction amount to be added to each pixel of an image to compress a dynamic range of the image by referring to a compression table that defines a relationship between the density of each pixel of the image and the compression amount for compressing the dynamic range of the image; a processing means for obtaining a processed image of which the dynamic range has been compressed by performing processing for compressing the dynamic range of the image by adding the correction amount to each pixel of the image; and a judgment means for judging whether an estimated change amount of the image by the processing for compressing the dynamic range, the estimated change amount being obtained from the compression table, is larger than a predetermined threshold value, wherein if the judgment is YES, the correction amount calculation means produces an unsharp image of the image and calculates the correction amount by using the unsharp image and by referring to the compression table, or if the judgment is NO, the correction amount calculation means calculates the correction amount by using the image instead of the unsharp image and by referring to the compression table. - View Dependent Claims (4, 7, 8, 9, 10, 11, 12)
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2. An image processing method to be implement on an image processing apparatus, the method comprising the steps of:
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calculating a correction amount to be added to each pixel of an image to compress a dynamic range of the image by referring to a compression table that defines a relationship between the density of each pixel of the image and the compression amount for compressing the dynamic range of based the image; obtaining a processed image of which the dynamic range has been compressed by performing processing for compressing the dynamic range of the image by adding the correction amount to each pixel of the image; judging whether an estimated change amount of the image by the processing for compressing the dynamic range, the estimated change amount being obtained from the compression table, is larger than a predetermined threshold value; and if the judgment is YES, producing an unsharp image of the image and calculating the correction amount by using the unsharp image and by referring to the compression table, or if the judgment is NO, calculating the correction amount by using the image instead of the unsharp image and by referring to the compression table. - View Dependent Claims (5)
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3. A computer readable medium encoded with a program for causing a computer to execute an image processing method, the program comprising the procedures for:
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calculating a correction amount to be added to each pixel of an image to compress a dynamic range of an image based on the image by referring to a compression table that defines a relationship between the density of each pixel of the image and the compression amount for compressing the dynamic range of the image; obtaining a processed image of which the dynamic range has been compressed by performing processing for compressing the dynamic range of the image by adding the correction amount to each pixel of the image; judging whether an estimated change amount of the image by the processing for compressing the dynamic range, the estimated change amount being obtained from the compression table, is larger than a predetermined threshold value; and if the judgment is YES, producing an unsharp image of the image and calculating the correction amount by using the unsharp image and by referring to the compression table, or if the judgment is NO, calculating the correction amount by using the image instead of the unsharp image and by referring to the compression table. - View Dependent Claims (6)
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Specification