how to choose image for compression

sir

i am compressing the image using transforms DCT DFT and DWT. the block of operation is

take image>>sub block into 8*8 >> apply DCT >> apply Quantization >> Apply RLE >> RL decoding>> Dequantization >>IDCT >> add sub blocks

Is this process give me compression ??

if no, What i need to do for compression ?

if yes, Where exactly the compression done??

what kind of image is to be use for this process??

All the images are already got compressed when capture by camera??

Answer 1

[Walter Roberson]

No, the process does not give you compression.

http://www.mathworks.co.uk/matlabcentral/answers/115357-image-compression-using-jpeg

Not all images are already compressed when captured by cameras.

[Jitesh Bhanushali]

should i remove the coefficient after quantization block to compress image??