Patent Number: 7,085,013

Title: Image processing apparatus including low-linear-density dot region detection unit, and image forming apparatus including the same

Abstract: An image processing apparatus includes a maximum/minimum density detecting unit which detects a center pixel of a matrix of N.times.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.

Inventors: Yamakawa; Shinji (Kanagawa, JP)

Assignee: Ricoh Company, Ltd.

International Classification: H04N 1/40 (20060101); G06T 5/00 (20060101); H04N 1/409 (20060101); G06T 5/30 (20060101)

Expiration Date: 8/01/02018