Calculation method of correlation search window ignoring some pixel data and navigation device using the same
AssigneePixart Imaging Inc.
InventorsKevin Len-Li LIM, Rizal Bin JAFFAR
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Abstract
There is provided a navigation device including an image sensor and a processor. The image sensor outputs a reference frame and a comparison frame. The processor calculates a correlation search window by changing a relative position of the comparison frame with respect to the reference frame. The processor ignores a part of pixel data of the comparison frame without being processed while calculating each correlation value of the correlation search window to reduce total computation load.
Claims20
A navigation device, comprising:
- an image sensor configured to output a reference frame and a comparison frame, wherein the reference frame is an image frame prior to the comparison frame;
- and
- a processor configured to
- calculate a correlation search window by changing a relative position of the comparison frame with respect to the reference frame, wherein the processor ignores a part of pixel data of the reference frame in calculating each correlation value of the correlation search window,
- calculate a correlation peak of the correlation search window,
- calculate full-resolution correlation values of the correlation peak and adjacent correlation values thereof, respectively, according to the comparison frame and the reference frame without ignoring pixel data, and
- mirror project the full-resolution correlation values of the adjacent correlation values within the correlation search window as a part of adjacent correlation values, which are outside the correlation search window, of the correlation peak when the correlation peak is at an edge position of the correlation search window.
A navigation device, comprising:
- an image sensor configured to output a reference frame and a comparison frame, wherein the comparison frame is an image frame prior to the comparison frame;
- and
- a processor configured to
- calculate a correlation search window by changing a relative position of the comparison frame with respect to the reference frame,
- not ignore any pixel data of the comparison frame while calculating inner correlation values of the correlation search window, and
- ignore a part of pixel data of the comparison frame while calculating edge correlation values surrounding the inner correlation values of the correlation search window.
A calculation method of a correlation search window of a navigation device, the navigation device comprising an image sensor and a processor, the calculation method comprising:
- sequentially outputting, by the image sensor, a reference frame and a comparison frame;
- calculating, by the processor, a correlation search window by changing a relative position of the comparison frame with respect to the reference frame;
- not ignoring any pixel data of the reference frame while calculating, by the processor, inner correlation values of the correlation search window;
- and
- ignoring a part of pixel data of the reference frame while calculating, by the processor, edge correlation values surrounding the inner correlation values of the correlation search window.
Dependencies are inferred from the claim text.