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US 5,331,426 AGranted
Image encoding method
AssigneeCanon Kabushiki Kaisha
InventorsShigeo Kato, Yasuhiko Yasuda, Hidefumi Ohsawa
Life of this patent
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Abstract
In an image encoding method in which a pixel of interest is predicted with reference to a plurality of pixels near the pixel of interest to be encoded, and encoding is performed on the basis of coincidence/noncoincidence between the predicted pixel and the pixel of interest, a parameter for predicting a pixel is changed on the basis of a rate of coincidence/noncoincidence of the predicted pixel and the pixel of interest.
Claims20
An image encoding system comprising:
- an input unit for inputting image data;
- a conversion unit for converting a resolution of the image data input by said input unit and generating low resolution image data;
- and
- an encoding unit for encoding the image data input by said input unit by using both the image data input by said input unit and the low resolution data generated by said conversion unit,
- wherein said encoding unit further comprises:
- storing means for storing a plurality of tables which are different from each other in varying a prediction parameter;
- providing means for providing a prediction parameter for use in predicting a data value of a pixel of interest referring to a plurality of pixels near the pixel of interest by using one of the tables stored in said storing means;
- predicting means for predicting the data value of the pixel of interest with reference to the plurality of pixels near the pixel of interest by using the prediction parameter;
- encoding means for encoding an image on the basis of coincidence/noncoincidence between the predicted data value and an actual value of the pixel of interest;
- and
- determining means for determining a table which is used by said providing means in accordance with the coincidence/noncoincidence between the predicted data value pixel and the actual value of the pixel of interest.
8 more elements
An image encoding apparatus comprising:
- storing means for storing a plurality of tables which are different from each other in varying a prediction parameter;
- providing means for providing a prediction parameter for use in predicting a value of a pixel of interest referring to a plurality of pixels near the pixel of interest by using one of the table stored in said storing means;
- predicting means for predicting the data value of the pixel of interest with reference to the plurality of pixels near the pixel of interest by using the prediction parameter;
- encoding means for encoding an image on the basis of coincidence/noncoincidence between the predicted data value and an actual value of the pixel of interest;
- determining means for determining a table which is used by said providing means in accordance with the coincidence/noncoincidence between the predicted data value and an actual value of the pixel of interest;
- and
- transmitting means for transmitting the image encoded by said encoding means.
4 more elements
An image decoding apparatus comprising:
- receiving means for receiving an encoded image data;
- decoding means for decoding the encoding image data received by said receiving means;
- and
- storing means for storing decoded image data decoded by said decoding means,
- wherein the encoded image data have been encoded by steps of:
- setting a plurality of tables which are different from each other in varying a prediction parameter;
- providing the pixel of interest with reference to the plurality of pixels near the pixel of interest by using the prediction parameter;
- predicting a data value of the pixel of interest with reference to the plurality of pixels near the pixel of interest by using the prediction parameter;
- encoding an image on the basis of coincidence/noncoincidence between the predicted data value and the actual value of the pixel of interest;
- and
- determining the table for providing the prediction parameter for use in encoding a succeeding pixel of interest, in accordance with the coincidence/noncoincidence between the predicted pixel and the pixel of interest.
8 more elements
Dependencies are inferred from the claim text.