| 摘要 |
PURPOSE: To obtain the high efficiency coder digitizing data with fewer information quantity by using transformation coding in a recording and transmission device for image and audio information. CONSTITUTION: Plural quantizers 11, 21, 31, 41 whose transformation coefficients differs from each other slightly are prepared in transformations coding of an image and audio signal and reproduced signals obtained by the inverse transformation to respective quantization results by IDCTs 13, 23, 33, 43 are compared respectively with an input signal at subtractors 14, 24, 34, 44 and errors are evaluated and a code selector 9 selects an optimum quantization result. Thus, accurate quantization taking a subjective characteristic or the like into account is attained to improve the coding efficiency. |
