Image processing apparatus and method
AssigneeCanon Kabushiki Kaisha
InventorMasami Kato
Life of this patent
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Abstract
A color-space conversion processor converts input digital image data into YUV color space, and a wavelet conversion processor performs wavelet conversion processing on the data. A face-area recognition processor extracts a face area in the image based on the obtained conversion coefficients. A quantization processor performs quantization processing on the input conversion coefficients while changing quantization coefficients used in the quantization processing in and out of the extracted face area. A variable-length coding processor encodes the quantized coefficients. A code synthesizing processor synthesizes the obtained respective color component code data with information indicating the face area extracted by the face-area recognition processor, and outputs the synthesized data as a code string.
Claims27
An image processing apparatus comprising:
- conversion means for converting input digital image data into coefficients based on spatial frequencies to obtain conversion coefficients;
- extraction means for extracting a specific area in an image represented by lowest frequency components for a converted image obtained by said conversion means, said specific area being extracted from the converted image by pattern matching between an area having a predetermined color component value range and a predetermined shape;
- and
- quantization means for performing quantization processing on said conversion coefficients of said converted image while changing a quantization characteristic in accordance with the specific area extracted by said extraction means.
An image processing method comprising:
- a conversion step of converting input digital image data into coefficients based on spatial frequencies to obtain conversion coefficients;
- an extraction step of extracting a specific area in an image represented by lowest frequency components for a converted image obtained by the conversion step, said specific area being extracted from the converted image by pattern matching between an area having a predetermined color component value range and a predetermined shape;
- and
- a quantization step of performing quantization processing on said conversion coefficients of the converted image while changing a quantization characteristic in accordance with the specific area extracted at said extraction step.
A storage medium containing a control program for causing a computer to compression-encode digital image data, said control program comprising:
- code of conversion process for converting input digital image data into coefficients based on spatial frequencies to obtain conversion coefficients;
- code of extraction process for extracting a specific area in an image represented by lowest frequency components for a converted image obtained by said conversion step, said specific area being extracted from the converted image by pattern matching between an area having a predetermined color component value range and a predetermined shape;
- and
- code of quantization process for performing quantization processing on said conversion coefficients of the converted image while changing a quantization characteristic in accordance with the specific area extracted by said extraction means.
Dependencies are inferred from the claim text.