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Re: Image compression on etrax



Hi Peter,
if you want to stick with jpeg, have a look at the ffmpeg program, if i 
recall correctly,
it comes with a very fast jpeg compression algorithm (rtjpeg).

Otherwise, wavelet compression algorithms could provide good performance.

Simon

Peter Fredriksson wrote:

> Hi again,
>
> It is 24 bit color images that I want to compress.
>
> Does not zlib use a similar algirithm as gzip. Compressing images with 
> gzip usually only makes it slightly smaller (if the image does not 
> contain large areas with only one color).
>
> I have been reading a bit about different compression codes but I cant 
> find any good place where the main issue is processing power, usually 
> it focuses on compression quality and/or compression factor. But when 
> you develop on an embedded system with limited processing power and no 
> fpu you really need to focus on performance.
>
> Regards,
> Peter
>
>
>
>
> At 10:42 2003-10-10 +0200, Walter Harms wrote:
>
>> Hi Peter,
>> i guess it depends what type of data you have. Real images or black &
>> white scans ? e.g. RLE is fast but mostly on BW images mor general is
>> libz.
>> There are several book in the wild discussing  Compression codes.
>>
>> regards,
>> walter
>>
>> - - - - - - - - - - - - - - Original Message - - - - - - - - - - - - - -
>> From: Peter Fredriksson <peter.fredriksson@xxxxxxx.se>
>> Subject: Image compression on etrax
>> Date: 10/10/03 09:37
>>
>> Hi all,
>>
>> Can anyone here on the list recommend some good image compression 
>> routine
>> that can be run on the etrax platform. I have tried  libjpeg, but
>> compressing a image that is 320*240x24bit takes more than 1.5 sec. The
>> perfect routine for me would provide loss-less compression. Speed is 
>> more
>> important than high compression.
>>
>> Thanks for your time,
>>
>> Peter
>>
>>
>>
>>
>>
>> ----------
>> Peter Fredriksson M.Sc.CE
>> Free2move AB            Office +46 (0)35 18 21 90
>> Pilefeltsgatan 77       Fax +46 (0)35 18 21 99
>> S-302 50 Halmstad       www.free2move.se <http://www.free2move.se/> 
>
> ------------------------------------------------------------------------
> Peter Fredriksson M.Sc.CE       
> Free2move AB            Office +46 (0)35 18 21 90
> Pilefeltsgatan 77       Fax +46 (0)35 18 21 99
> S-302 50 Halmstad       _www.free2move.se_ <http://www.free2move.se/>_
> _