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US 7,254,254 B2Granted
Method of evaluating quality of image and use thereof
AssigneeBrother Kogyo Kabushiki Kaisha
InventorsMasashi Ueda, Takuma Kuno
Life of this patent
Estimating the term…
Abstract
A method of evaluating the quality of an image includes a step of determining at least a parameter concerning a zone or a parameter concerning a distribution pattern of sampling points within the zone. This step is performed based on the image. For each zone, Fourier analysis is performed using the optical characteristic values of the respective sampling points within the zone, and the image quality of each zone is obtained. The quality of the image is then determined based on the image quality of each zone within the image. A suitable zone and distribution pattern of sampling points are employed in evaluating the quality of an image.
Claims12
A method of evaluating the quality of an image comprising at least one zone, wherein the method comprises the steps of:
- determining at least one of a parameter associated with at least one zone and a parameter associated with a distribution pattern of sampling points within the at least one zone, wherein the at least one parameter is determined based on at least one of the following:
- (1) a distance between an observer and the image,
- (2) a size of the image, and
- (3) a type of the image;
- delineating the at least one zone in the image,
- wherein the at least one zone is delineated based on the determined at least one parameter when the determined parameter is associated with the at least one zone, and
- wherein the at least one zone is delineated based on a predetermined parameter when the determined parameter is not associated with the at least one zone;
- disposing the sampling points within the at least one zone,
- wherein the sampling points are disposed based on the determined at least one parameter when the determined parameter is associated with the distribution pattern, and
- wherein the sampling points are disposed based on a predetermined parameter when the determined parameter is not associated with the distribution pattern;
- identifying data that indicates a position and an optical characteristic value of each of the sampling points within the at least one zone which are determined based at least on the at least one parameter;
- performing Fourier analysis on the data relevant to the at least one zone to obtain an image quality of the at least one zone;
- and
- determining the quality of the image based on the image quality of the at least one zone.
11 more elements
A device for assisting in evaluating the quality of an image comprising at least one zone, the device comprising:
- means for determining at least one of a parameter associated with the at least one zone and a parameter associated with a distribution pattern of sampling points within the at least one zone, wherein the at least one parameter is determined based at least one of the following:
- (1) a distance between an observer and the image,
- (2) a size of the image, and
- (3) a type of the image;
- means for delineating the at least one zone in the image,
- wherein the at least one zone is delineated based on the determined at least one parameter when the determined parameter is associated with the at least one zone, and
- wherein the at least one zone is delineated based on a predetermined parameter when the determined parameter is not associated with the at least one zone;
- means for disposing the sampling points within the at least one zone,
- wherein the sampling points are disposed based on the determined at least one parameter when the determined parameter is associated with the distribution pattern, and
- wherein the sampling points are disposed based on a predetermined parameter when the determined parameter is not associated with the distribution pattern;
- means for identifying data that indicates a position and an optical characteristic value of each of the sampling points within the at least one zone which are determined based on the at least one parameter;
- means for performing Fourier analysis on the data relevant to the at least one zone to obtain an image quality of the at least one zone;
- and
- means for determining the quality of the image based on the image quality of the at least one zone.
11 more elements
An image forming device, comprising:
- means for forming an image comprising at least one zone;
- means for determining at least one of a parameter associated with the at least one zone and a parameter associated with a distribution pattern of sampling points within the at least one zone, wherein the at least one parameter is determined based on at least one of the following:
- (1) a distance between an observer and the image,
- (2) a size of the image, and
- (3) a type of the image;
- means for delineating the at least one zone in the image,
- wherein the at least one zone is delineated based on the determined at least one parameter when the determined parameter is associated with the at least one zone, and
- wherein the at least one zone is delineated based on a predetermined parameter when the determined parameter is not associated with the at least one zone;
- means for disposing the sampling points within the at least one zone,
- wherein the sampling points are disposed based on the determined at least one parameter when the determined parameter is associated with the distribution pattern, and
- wherein the sampling points are disposed based on a predetermined parameter when the determined parameter is not associated with the distribution pattern;
- means for measuring an optical characteristic value of the image at least at each of the sampling points within the at least one zone which are determined based on the determined parameter;
- means for performing Fourier analysis on the optical characteristic values of the sampling points within the at least one zone to obtain an image quality of the at least one zone;
- and
- means for determining a quality of the image based on the image quality of the at least one zone.
12 more elements
A computer program product that includes a computer-readable medium having computer-readable instructions stored thereon for execution by a processor, wherein execution of the computer-readable instructions causes said computer program product to perform the steps of:
- determining at least one of a parameter associated with at least one zone and a parameter associated with a distribution pattern of sampling points within the at least one zone, wherein the at least one parameter is determined based on at least one of the following:
- (1) a distance between an observer and the image,
- (2) a size of the image, and
- (3) a type of the image;
- delineating the at least one zone in the image,
- wherein the at least one zone is delineated based on the determined at least one parameter when the determined parameter is associated with the at least one zone, and
- wherein the at least one zone is delineated based on a predetermined parameter when the determined parameter is not associated with the at least one zone;
- disposing the sampling points within the at least one zone,
- wherein the sampling points are disposed based on the determined at least one parameter when the determined parameter is associated with the distribution pattern, and
- wherein the sampling points are disposed based on a predetermined parameter when the determined parameter is not associated with the distribution pattern;
- identifying data that indicates a position and an optical characteristic value of each of the sampling points within the at least one zone which are determined at least based on the at least one parameter;
- performing Fourier analysis on the data relevant to the at least one zone to obtain an image quality of the at least one zone;
- and
- determining a quality of the image based on the image quality of the at least one zone.
11 more elements
Dependencies are inferred from the claim text.