| 摘要 |
PROBLEM TO BE SOLVED: To provide a data compressing method, a data expanding method, and a device therefore which enable improvement of the compression efficiency of discontinuously appearing data and reduction of the consumption of storage media and data transfer amount inside and outside the device for Packbits compression. SOLUTION: A CPU in a printer controller when generating a Packbits object needed for image generation decides data of high appearance frequency among pieces of discontinuous data and converts selected 8-bit data into a 4-bit command (max 16 bytes). The 8-bit real data is stored in a Packbits expanding device in an image generation part before image processing starts. After the image processing start, the Packbits expanding device reads corresponding 8-bit data out of the 4-bit data inputted from the CPU one after another and outputs image data. |
