Scalable test target and method for measurement of camera image quality
AssigneeNokia Corporation
InventorHarri J. Ojanen
Life of this patent
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Abstract
An improved test target pattern that can be used in the testing of image quality for digital images taken with a camera module, the camera module either being a stand-alone product or being incorporated into a device such as a mobile telephone. With the present invention, several different image quality aspects can be monitored and measured using a single test pattern. Previously, multiple test patterns would have had to have been used for such a task.
Claims13
A method of measuring the quality of an image captured by a camera module, the image comprising a plurality of concentric annuli, at least one of the plurality of concentric annuli comprising a plurality of rectangularly-shaped segments of alternating colors, the method comprising:
- measuring vignetting of the captured image;
- generating a corrected image based upon the measured vignetting;
- detecting corners and determining a center of the corrected image, the detected corners and determined center being used to group the annuli of the corrected image;
- grouping the detected corners based upon their distances from the determined center;
- measuring a tilt of the corrected image and generating a recorrected image based upon the measured tilt;
- and
- refinding the annuli in the recorrected image.
A computer program product for measuring the quality of an image captured by a camera module, the image comprising a plurality of concentric annuli, at least one of the plurality of concentric annuli comprising a plurality of rectangularly-shaped segments of alternating colors, the computer program product comprising:
- computer code for measuring vignetting of the captured image;
- computer code for generating a corrected image based upon the measured vignetting;
- computer code for detecting corners and determining a center of the corrected image, the detected corners and determined center being used to group the annuli of the corrected image;
- computer code for grouping the detected corners based upon their distances from the determined center;
- computer code for measuring a tilt of the corrected image and generating a recorrected image based upon the measured tilt;
- and
- computer code for refunding the annuli in the recorrected image.
An electronic device, comprising:
- a processor;
- and
- a memory unit operatively connected to the processor and including a computer program product for measuring the quality of an image captured by a camera module, the image comprising a plurality of concentric annuli, at least one of the plurality of concentric annuli comprising a plurality of rectangularly-shaped segments of alternating colors, the computer program product comprising:
- computer code for measuring vignetting of the captured image;
- computer code for generating a corrected image based upon the measured vignetting;
- computer code for detecting corners and determining a center of the corrected image, the detected corners and determined center being used to group the annuli of the corrected image;
- computer code for grouping the detected corners based upon their distances from the determined center;
- computer code for measuring a tilt of the corrected image and generating a recorrected image based upon the measured tilt;
- and
- computer code for refinding the annuli in the recorrected image.
Dependencies are inferred from the claim text.