多媒体技术原理 图形和图像数据表现课件.pptVIP

Chapter 3Graphics Image Data Representation;3.1 Graphics Image Data Types;1-bit Images;Fig. 3.1: Monochrome 1-bit Lena image.;8-bit Gray-level Images;8-bit Gray-level Images;Fig. 3.3: Grayscale image of Lena.;8-bit Gray-level Images;Fig. 3.2: Bit-planes for 8-bit grayscale image.;Bit-planes for 8-bit grayscale image;Multimedia Presentation;Multimedia Presentation;calculation ;Dithering;Dithering;Dithering;Dithering;An algorithm for ordered dither;Dithering;Image Data Types;24-bit Color Images;Fig. 3.5: High-resolution color and separate R, G, B color channel images. (a): Example of 24-bit color image “forestfire.bmp”. (b, c, d): R, G, and B color channels for this image;8-bit Color Images;Fig. 3.6: 3-dimensional histogram of RGB colors in “forestfire.bmp”.;8-bit Color Images;8位索引图像;Color Look-up Tables (LUTs);Color Look-up Tables (LUTs);Fig. 3.9: Color-picker for 8-bit color: each block of the color-picker corresponds to one row of the color LUT;Examples;How to devise a color look-up table;How to devise a color look-up table;Fig. 3.11 Histogram of R bytes for the 24-bit color image “forestfire.bmp” results in a “0” bit or “1” bit label for every pixel. For the second bit of the color table index being built, we take R values less than the R median and label just those pixels as “0” or “1” according as their G value is less than or greater than the median of the G value, just for the “0” Red bit pixels. Continuing over R, G, B for 8 bits gives a color LUT 8-bit index.;3.2 Popular File Formats;GIF;GIF;GIF87;GIF;GIF;GIF;GIF;GIF;JPEG;JPEG;JPEG;PNG;*;*;*;TIFF;EXIF;Graphics Animation Files ;PS and PDF;PS and PDF;Some Other JPEG Formats;Some Other JPEG Formats;Some Other JPEG Formats;3.3 Further Exploration;Assignments