TAILIEUCHUNG - The Essential Guide to Image Processing- P15

The Essential Guide to Image Processing- P15:We are in the middle of an exciting period of time in the field of image processing. Indeed, scarcely a week passes where we do not hear an announcement of some new technological breakthrough in the areas of digital computation and telecommunication. | Quantization 427 50 100 150 200 250 300 350 400 450 500 50 100 150 200 250 300 350 400 450 500 270 280 290 300 310 320 180 190 200 210 220 230 FIGURE The original 512 X 512 Lena image top with an 8 X 8 block bottom identified with black boundary and with one corner at 209 297 . 428 CHAPTER 17 JPEG and JPEG2000 187 188 189 202 209 175 66 41 191 186 193 209 193 98 40 39 188 187 202 202 144 53 35 37 189 195 206 172 58 47 43 45 197 204 194 106 50 48 42 45 208 204 151 50 41 41 41 53 209 179 68 42 35 36 40 47 200 117 53 41 34 38 39 63 FIGURE The 8 x 8 block identified in Fig. . FIGURE DCT of the 8 x 8 blockin Fig. values of q m n are restricted to be integers with 1 q m n 255 and they determine the quantization step for the corresponding coefficient. The quantized coefficient is given by qX m n X m n _q m n round A quantization table or matrix is required for each image component. However a quantization table can be shared by multiple components. For example in a luminance-plus-chrominance Y Cr Cb representation the two chrominance components usually share a common quantization matrix. JPEG quantization tables given in Annex K of the standard for luminance and components are shown in Fig. . These tables were obtained from a series of psychovisual experiments to determine the visibility thresholds for the DCT basis functions for a 760 X 576 image with chrominance components downsampled by 2 in the horizontal direction and at a viewing distance equal to six times the screen width. On examining the tables we observe that the quantization table for the chrominance components has larger values in general implying that the .

• Đồ họa - Thiết kế - Flash
• thiết kế flash
• thiết kế web
• giáo trình CSS
• thủ thuật cắt html
• photoshop căn bản
• đồ họa máy tính
• Thiết kế đa truyền thông với Adobe Flash CS6
• Adobe Flash CS6
• Chỉnh sửa ảnh Photoshop từ Flash
• Chèn đoạn phim Flash vào Dreamweaver
• Chỉnh sửa đoạn phim Flash từ Dreamweaver
• Nhập file AI từ Illustrator vào Flash
• Tích hợp nội dung Flash
• flash cs5
• thủ thuật flash cs5
• tài liệu flash cs5
• học flash cs5
• ebook flash cs5