Re: weird usages of HP 49 (original) Message #3 Posted by Bill Wiese on 17 Nov 2005, 5:21 p.m., in response to message #2 by unspellable
Well, you'd first have to decompress the JPEG image into actual pixels. That's a time-consuming process for native Saturn CPU instruction set. Dropping back into the ARM instruction set for the HP49 may be very useful for speed.
If the image is large and the aspect ratio is same/near to that of HP49 screen, and 8X downsampling would work, then the DC coeffecients of the 8x8 DCT blocks could just be used. This avoids the extra crunching to extract all the other pixels - as the DCT's DC coefficient is just the avg value of all the pixels in that 8x8 block.
Bill Wiese
San Jose, CA USA
1234 to delete
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