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... once I retrieve the picture stored on this SD-card (if I succeed to do it :-) ), how can I display it on the screen? Do you know if there is a sort of IP to do that or should I just look at the characteristic of bmp image for ex to get the pixels informations?
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I think that the more difficult part is to build everything for reading the bmp file from SD card. Then the road is downhill.
Infact, getting the pixel information from bmp file is rather simple (see for example
http://en.wikipedia.org/wiki/bmp_file_format). I'm assuming you already have the VGA display driver, so you simply have to turn on the required image pixels.
I'm also assuming you are planning to use Nios or other processor to handle all the stuff.
Cris