Invention Grant
- Patent Title: Image processing apparatus including low-linear-density dot region detection unit, and image forming apparatus including the same
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Application No.: US10662415Application Date: 2003-09-16
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Publication No.: US07085013B2Publication Date: 2006-08-01
- Inventor: Shinji Yamakawa
- Applicant: Shinji Yamakawa
- Applicant Address: JP
- Assignee: Ricoh Company, Ltd.
- Current Assignee: Ricoh Company, Ltd.
- Current Assignee Address: JP
- Agency: Dickstein Shapiro Morin & Oshinsky LLP
- Priority: JP2001-157506 20010525; JP2002-137710 20020513
- Main IPC: H04N1/40
- IPC: H04N1/40 ; H04N1/409 ; G06T5/00 ; G06T5/30

Abstract:
An image processing apparatus includes a maximum/minimum density detecting unit which detects a center pixel of a matrix of N×N pixels in image data that has a maximum or minimum density. A determination unit determines whether the absolute value of a difference between an average of densities of diagonal pixels of the matrix and a density of the center pixel is larger than a threshold value. A peak pixel detecting unit detects peak pixels of the matrix, each peak pixel being the center pixel having a maximum or minimum density, and the absolute value of the difference with respect to the center pixel being larger than the threshold value. A dot region detecting unit detects one of neighboring pixels of the matrix as being a dot region based on the number of the peak pixels in a target region and the number of the peak pixels in each of neighboring regions.
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