Image processing apparatus, control method, and storage medium to detect a sheet edge based on marks printed on an adjustment chart and acquired regions of interest images
AssigneeCanon Kabushiki Kaisha
InventorsHirokazu Tamura, Satoshi Ikeda
Life of this patent
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Abstract
An image processing apparatus having a reading device to read an image from a sheet includes one or more controllers to perform operations. One image is read from one sheet by using the reading device. Edge detection processing is executed on the one image. At least one pair of edges is determined from among a plurality of edges based on information of the plurality of edges detected in the edge detection processing and size information of the one sheet.
Claims17
An image reading apparatus comprising:
- a conveyor;
- a reader configured to read an image from a sheet conveyed by the conveyor, wherein the sheet is an adjustment chart document having marks printed as part of the image at predetermined positions, and having edges that include a left edge, a right edge, a top edge, and a bottom edge;
- and
- one or more processors configured to perform operations including:
- causing the reader to read the image from the sheet to obtain a read image,
- acquiring, from the read image and based on the marks printed at the predetermined positions, left and right regions of interest (ROI) images, each including at least a shadow of a respective edge of the sheet, and
- after acquiring the left and right ROI images, performing edge detection processing as follows:
- extracting, from the left and right ROI images, a plurality of first sheet edge candidates and a plurality of second sheet edge candidates on an opposite edge from the first sheet edge candidates, by performing a binarization process and Hough transform process on data resulting from the binarization process, and
- determining a sheet edge pair from among the plurality of first sheet edge candidates and the plurality of second sheet edge candidates.
A method for controlling an image reading apparatus having a conveyor, and a reader configured to read an image from a sheet conveyed by the conveyor, wherein the sheet is an adjustment chart document having marks printed as part of the image at predetermined positions, and having edges that include a left edge, a right edge, a top edge, and a bottom edge, the method comprising:
- reading the image from the sheet to obtain a read image;
- acquiring, from the read image and based on the marks printed at the predetermined positions, left and right regions of interest (ROI) images, each including at least a shadow of a respective edge of the sheet;
- and
- after acquiring the left and right ROI images, performing edge detection processing as follows:
- extracting, from the left and right ROI images, a plurality of first sheet edge candidates and a plurality of second sheet edge candidates on an opposite edge from the first sheet edge candidates, by performing a binarization process and Hough transform process on data resulting from the binarization process, and
- determining a sheet edge pair from among the plurality of first sheet edge candidates and the plurality of second sheet edge candidates.
A non-transitory computer-readable storage medium storing computer-executable instructions for causing a computer to execute a method for controlling an image reading apparatus having a conveyor, and a reader configured to read an image from a sheet conveyed by the conveyor, wherein the sheet is an adjustment chart document having marks printed as part of the image at predetermined positions, and having edges that include a left edge, a right edge, a top edge, and a bottom edge, the method comprising:
- reading the image from the sheet to obtain a read image;
- acquiring, from the read image and based on the marks printed at the predetermined positions, left and right regions of interest (ROI) images, each including at least a shadow of a respective edge of the sheet;
- and
- after acquiring the left and right ROI images, performing edge detection processing as follows:
- extracting, from the left and right ROI images, a plurality of first sheet edge candidates and a plurality of second sheet edge candidates on an opposite edge from the first sheet edge candidates, by performing a binarization process and Hough transform process on data resulting from the binarization process, and determining a sheet edge pair from among the plurality of first sheet edge candidates and the plurality of second sheet edge candidates.
Dependencies are inferred from the claim text.