Image processing apparatus and method setting thresholds of dither patterns based on density range and generating binary data depending on thresholds of target pixels

摘要

An image processing apparatus includes a generation unit; wherein a first dither pattern and a second dither pattern have same threshold values that are set for same pixels in a first gradation range, and have different threshold values that are set for same pixels in a second gradation range that exceeds the first gradation range; and the generation unit sets a first threshold value for forming dots of the first dither pattern, and generates a first binary data according to whether or not a threshold value corresponding to a target pixel of the first dither pattern is included in the first threshold value, and sets a second threshold value for forming dots of the second dither pattern, and generates a second binary data according to whether or not a threshold value corresponding to a target pixel of the second dither pattern is included in the second threshold value.

主权项

1. An image processing apparatus comprising:
an acquisition unit configured to acquire first multi-value data and second multi-value data based on input image data; and a generation unit configured to generate first binary data and second binary data for printing dots by performing quantization processing using a dithering method on the first multi-value data and the second multi-value data; wherein a first dither pattern that is used for the first multi-value data and a second dither pattern that is used for the second multi-value data have same threshold values that are set for same pixels in a first gradation range, and have different threshold values that are set for same pixels in a second gradation range that exceeds the first gradation range; and the generation unit sets a first threshold value for forming dots of the first dither pattern based on the first multi-value data and the second multi-value data, and generates the first binary data according to whether or not a threshold value corresponding to a target pixel of the first dither pattern is included in the first threshold value, and sets a second threshold value for forming dots of the second dither pattern based on the second multi-value data and the first multi-value data, and generates the second binary data according to whether or not a threshold value corresponding to a target pixel of the second dither pattern is included in the second threshold value.