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JPEG Encoder

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More compress ratio #5
Open khaleghian opened this issue over 13 years ago
khaleghian commented over 13 years ago

Dear Michal, Hello, What changes have to do in mkjpeg for more compress ratios? It will be done simply by changing some parameters in the code or it is more complicated. Thnaks

mikel262 commented over 13 years ago

This is done via huffman AC and DC quantization tables. You can use freely available Irfanview and Jpegsnoop to extract those tables for different quality settings per given image.

Michal

khaleghian commented over 13 years ago

Thanks

khaleghian commented over 13 years ago

Thanks

steve550 commented over 11 years ago

Hi Michal

I have used Infraview and Jpegsnoop to extract Quantization tables and have got some good results. However my image is always larger than the Infraview version. So far i have not changed the Huffman tables as i am i bit unclear on how to change them, could you help me please with this?

Steve

mikel262 commented over 11 years ago

For Huffman tables you need to modify Header RAM hex file. See 1.10.1 Header RAM Programming in documentation.

Michal

steve550 commented over 11 years ago

Hi Michal

I have used Infraview and Jpegsnoop to extract Quantization tables and have got some good results. However my image is always larger than the Infraview version. So far i have not changed the Huffman tables as i am i bit unclear on how to change them, could you help me please with this?

Steve

steve550 commented over 11 years ago

Ok thanks Michal, i'll try that!

steve550 commented over 11 years ago

Ok thanks Michal, i'll try that!

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