Image quality evaluation device, terminal device, image quality evaluation system, image quality evaluation method and computer-readable recording medium for storing programs
First Claim
1. An image quality evaluation device for evaluating the quality of an image in which various pixels in the original image have been periodically thinned, or an image in which multiple pixels in the original image have been periodically summed on brightness, obtained by a shooting photographic subject including a periodic pattern that fluctuates periodically in one direction, wherein the image quality evaluation device includes:
- a Fourier transform unit that accomplishes a two-dimensional Fourier transform on the image to obtain two-dimensional spatial frequency spectrum components; and
an analysis unit that, among the two-dimensional spatial frequency spectrum components obtained by the Fourier transform unit, analyzes the resolution of the image on the basis of spectrum components of spatial frequencies included in the periodic pattern, and analyzes the deterioration of the image on the basis of spectrum components other than these;
wherein the analysis unit determines whether or not jaggies have occurred on the basis of the spectrum components of spatial frequencies corresponding to the period of the thinning or the brightness summing.
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Accused Products
Abstract
The present invention evaluates the quality of an image shot by a terminal device in a state closer to that seen with the eye. A computer evaluates the quality of an image obtained by shooting a photographic subject including a periodic pattern that fluctuates periodically in one direction. A Fourier transform unit accomplishes a two-dimensional Fourier transform on the image to obtain two-dimensional spatial frequency spectrum components. An analysis unit analyzes the resolution of the image on the basis of spectrum components of spatial frequencies included in the periodic pattern, among the two-dimensional spatial frequency spectrum components obtained by the Fourier transform unit, and analyzes the deterioration of the image on the basis of spectrum components other than these.
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Citations
12 Claims
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1. An image quality evaluation device for evaluating the quality of an image in which various pixels in the original image have been periodically thinned, or an image in which multiple pixels in the original image have been periodically summed on brightness, obtained by a shooting photographic subject including a periodic pattern that fluctuates periodically in one direction, wherein the image quality evaluation device includes:
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a Fourier transform unit that accomplishes a two-dimensional Fourier transform on the image to obtain two-dimensional spatial frequency spectrum components; and an analysis unit that, among the two-dimensional spatial frequency spectrum components obtained by the Fourier transform unit, analyzes the resolution of the image on the basis of spectrum components of spatial frequencies included in the periodic pattern, and analyzes the deterioration of the image on the basis of spectrum components other than these; wherein the analysis unit determines whether or not jaggies have occurred on the basis of the spectrum components of spatial frequencies corresponding to the period of the thinning or the brightness summing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An image quality evaluation method for evaluating the quality of an image in which various pixels in the original image have been periodically thinned, or an image in which multiple pixels in the original image have been periodically summed on brightness, obtained by shooting a photographic subject including a periodic pattern that fluctuates periodically in one direction, wherein the image quality evaluation method includes:
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a Fourier transform process that accomplishes a two-dimensional Fourier transform on the image to obtain two-dimensional spatial frequency spectrum components; and an analysis process that, among the two-dimensional spatial frequency spectrum components obtained in the Fourier transform process, analyzes the resolution of the image on the basis of the spectrum components of spatial frequencies included in the periodic pattern, and analyzes the deterioration of the image on the basis of spectrum components other than these, wherein the analysis unit determines whether or not jaggies have occurred on the basis of the spectrum components of spatial frequencies corresponding to the period of the thinning or the brightness summing.
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12. A non-transitory computer-readable recording medium for storing a program for evaluating the quality of an image in which various pixels in the original image have been periodically thinned, or an image in which multiple pixels in the original image have been periodically summed on brightness, obtained by shooting a photographic subject including a periodic pattern that fluctuates periodically in one direction, this program causing a computer to function as:
- a Fourier transform means that accomplishes a two-dimensional Fourier transform on the image to obtain two-dimensional spatial frequency spectrum components; and
an analysis means that, among the two-dimensional spatial frequency spectrum components obtained by the Fourier transform means, analyzes the resolution of the image on the basis of spectrum components of spatial frequencies included in the periodic pattern, and analyzes the deterioration of the image on the basis of spectrum components other than these, wherein the analysis unit determines whether or not jaggies have occurred on the basis of the spectrum components of spatial frequencies corresponding to the period of the thinning or the brightness summing.
- a Fourier transform means that accomplishes a two-dimensional Fourier transform on the image to obtain two-dimensional spatial frequency spectrum components; and
Specification