JEPG-Students Report-Group B

PEG compression
JPEG stands for Joint photographic experts group. It is the first interanational standard in image compression. It is widely used today. It could be lossy as well as lossless.
algorithm JPEG compression
The first step is break into 8 x 8 blocks. Then starting from the first block, map the range from -128 to 127. After that you have to find the discrete Fourier transform of the matrix. The result of this should be quantized. The last step is to apply encoding in the zig zag manner and do it till you find all zero. Save this one dimensional array and you are done. Note. You have to repeat this procedure for all the block of 8x 8.
How jpeg compression works
First step is to divide an image into blocks with each having dimensions of 8 x8.
Let’s for the record, say that this 8x8 image contains the following values.
The range of the pixels intensities now are from 0 to 255. We will change the range from -128 to 127.
Subtracting 128 from each pixel value yields pixel value from -128 to 127. After subtracting 128 from each of the pixel value, we got the following results.
The next step is to take the two-dimensional DCT, which is given by:
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