JPEG COMPRESSION
The JPEG image compression technique consists of 5 functional stages. 1. an RGB to YCC color space conversion, 2. a spatial subsampling of the chrominance channels in YCC space 3. the transformation of a blocked representation of the YCC spatial image data to a frequency domain representation using the discrete cosine transform, 4. a quantization of the blocked frequency domain data according to a user-defined quality factor, and finally 5. the coding of the frequency domain data, for storage, using Huffman coding.
The human visual system relies more on spatial content and acuity than it does on color for interpretation. For this reason, a color photograph, represented by a red, green, and blue image, is transformed to different color space that attempts to isolate these two components of image content; namely the YCC or luminance/chrominancered/chrominanceblue color space. This color space transformation is performed on a pixel-by-pixel basis with the digital counts being converted according to the following rules   GPEG compression stap: jpeg compressed image data > decoding > de-quantization > inverse DCT > up-sampling > color transform > raw image data > color transform > downsampling > forward DCT > quantization > en coding. Â
PNG COMPRESSION PNG full form name:[ protable network graphics ] How does it work? When you upload a PNG (Portable Network Graphics) file, similar colors in your image are combined. This technique is called “quantization”. By reducing the number of colors, 24-bit PNG files can be converted to much smaller 8-bit indexed color images. All unnecessary metadata is stripped too. The result: better PNG files with 100% support for transparency. Is it supported everywhere? The files produced by TinyPNG are displayed perfectly on all modern browsers including mobile devices. Still need to support Internet Explorer 6? It normally ignores PNG transparency and displays a solid background color. With TinyPNG the background becomes transparent again. Binary transparency without any workarounds!
TIFF COMPRESSION
The TIFF image format is generally regarded as the gold standard for long-term storage of static image data. It is flexible, widely supported, and rich in its treatment of both image data and metadata. Its historical disadvantage has been its large file sizes; this can, however, be mitigated by the use of compression, support for which is built into the format and described in the TIFF compression tag for each file.
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