Yutaka Koshi

Study for high-resolution color-image-coding approach for office system

Distributed office systems employ the image exchange facilities such as image input/output, handling a softcopy, image filing service and so on. This paper presents a study of the segmented image exchange approach suit well for block based image coding and image processing schemes. From the result of the feasibility study, the segmented image formatting criterion provides a well-designed quantization-table set for DCT coding scheme. The 400 spi full-tone image coding simulation of the segmented adaptive quantization for DCT coding shows the better SNR and the perceptually better image quality than that of the conventional scheme. To select the quantization-table in the decoder, this scheme requires 3-bit header for every coded block. However, it enables another image processing features in a reconstructed image.

High-resolution color image coding scheme for office systems

There is great interest in having office systems that adopt the image coding to enable high resolution and high quality document management. Network-based office systems require two classes of procedures. The first requires a new “ internal coding” scheme for integrated image processing and editing operations. The second corresponds to image data interchange between system components through the network and can be implemented using conventional image coding scheme such as JPEG. This paper deals with a new image coding scheme which is designed for internal coding facility based on the adaptive block truncation coding. This scheme can perform block by block fixed rate coding and editing within an encoded form. The simulation results show the feasibility of the proposed scheme at compression ratios of 4 to 8.