| 摘要 |
<p>PROBLEM TO BE SOLVED: To adjust a compression rate suitable for image quality of an image, when compression coding is applied to the image photographed via an aperture. SOLUTION: An image input section 2 of the image input device 1 picks up an image by a CCD 15 via a lens 11 and an aperture 13, an A/D converter 16 digitizes the photographed image data and stores the digital data in a frame memory 17. A focusing device 12 adjusts the position of the lens 11, and an aperture controller 14 informs an image quality setting device 24 of a size of a diameter of the aperture 13 in the case of image pickup. Furthermore, an image coding section 3 applies compression coding to the image data from the frame memory 17, based on a quantization table 23 by a discrete cosine transform device 21, a quantizer 22, and a Huffman coder 25 by means of, e.g. the joint photographic experts group(JPEG) system. In this case, the image quality setting device 24 increases a compression rate of coding as the informed diameter of the aperture 13 increases and decreases the compression rate of coding as the notified diameter of the aperture 13 decreases through the revision of a setting value of the quantization table 23.</p> |
