| 摘要 |
<p>PURPOSE:To obtain the number of original picture elements of the best image quality with the same code quantity by encoding the coefft. of conversion obtd. by orthogonal conversion at an arbitrary compression ratio and executing conversion to the number of picture elements and variable length encoding in accordance with the code quantity information thereof. CONSTITUTION:An image signal 1 is converted to an image digital signal which is held in an image memory 3. A number-ofpicture-element conversion section 4 converts the signal to the number of the original picture elements assigned by a control signal for the number of the original picture elements in accordance with the image digital signal of the image memory 3 and sends the number to an orthogonal conversion section 5 at every block of MXN (M, N are arbitrary integers) picture elements. The orthogonal conversion is executed, block by block, and a conversion code 6 is outputted in the orthogonal conversion section 5. The conversion code 6 is encoded with the compression ratio assigned by a compression ratio control signal 11 in a variable length encoding section 7 and is made into a code output 13 together with information quantity information 12. The images having the best image quality in the assigned code quantity is encoded and decoded in this way.</p> |
