Computer Graphics Essay Example | Topics and Well Written Essays - 1250 words

computing device Graphics - Essay ExampleWallace, 2001. pp3-6The JPEG compression algorithm involves three breaker points - Colour Space Conversion ( wild-Green-Blue triplets mapped to Luminance-Chrominance Blue-Chrominance Red triplets), Segmentation into 8x8 pixel blocks, and Discrete Cosine Transformation (image transformation from spatial flying field to frequency domain representation) encoding stage that includes Quantization (sorting the output waveform of DCT), Zigzag Scan (sorting the frequency coefficients from low to high), and stochasticity cryptanalysis (Huffman Coding and Arithmetic Coding).The encoding and decoding algorithms for JPEG images are shown in figures 1 and 2 respectively. compressing is used to reduce the file sizes such that they can be used on web pages or documentation or any other light weight graphics applications. The 8x8 blocks of source images are frontmost shifted from unsigned integers to signed integers and then are applied to the Forward Discrete Cosine Transformer (FDCT). To decode the flavourless image to achieve the 8x8 blocks again, they are applied to the entropy decoder whereby the output is taken out from contrary Discrete Cosine Transformer (IDCT). The final processing step of DCT encoder is the entropy coding that achieves additional compression by encoding the quantized DCT coefficients based on statistical characteristics. There are two types of Entropy Coding methods - Huffman coding and Arithmetic coding. Huffman coding removes one or more sets of Huffman code tables whereas Arithmetic coding doesnt require any external tables (although statistical conditioning tables as inputs can improve coding efficiency). The quantization stage of JPEG algorithm results in loss of information, thus making JPEG standard a lossy compression technique. Wallace, 2001. pp3-6 coalition Ratios and JPEG image formatsCompression is specified in terms of consequences per pixel including the chrominance and luminance compo nents) called the compression bit rate. higher(prenominal) the value of bits per pixel, better would be the image step. The JPEG standard recommends the following mapping of image quality with bit rates in colored images having hold backly complex scenes0.25 to 0.5 bits per pixel The output image shall possess moderate to good quality 0.5 to 0.75 bits per pixel The output image shall possess good to very good quality 0.75 to 1.5 bits per pixel The output image shall possess excellent quality 1.5 to 2.0 bits per pixel The output image shall be practically non-distinguishable from the original imageThe improved version of original JPEG technology is JPEG 2000 that provides better rate