It's not greyscale per se that is bad w/ rle encoding, it's dithered
images. There are other color-reduction algorithms that may work
better with compression than dithering does. Check to see if the
paint program you are using to convert the images has some options.
--
-Richard M. Hartman
[EMAIL PROTECTED]
186,000 mi/sec: not just a good idea, it's the LAW!
Kijang Jung wrote in message <25175@palm-dev-forum>...
>
>I'm dealing with grayscale images dithered from 256-color, or true color
>images.
>In this case, Scanline and RLE are both NOT good to compress grayscales. So
>now I'm implementing LZW to compress grayscale images. LZW can compress
>grayscale image to about its half size.
>I already tested Scanline coding which is supported by PalmOS, especially
by
>'WinDrawBitmap() function. (so that it's very convenient to display the
>bitmap compressed with scanline coding.)
>If you need the scanline coding, let me know that. I will send you my
code..
>
>Kijang Jung
>SolidStreaming Inc.
>
>"Bob Whiteman" <[EMAIL PROTECTED]> wrote in message
>news:24986@palm-dev-forum...
>>
>> Application compression in the OS, huh? Is the decompression algorithm
>> exposed anywhere? What algorithm is used?
>>
>> Also out of curiosity, bitmaps can be compressed using scan line
>compression
>> or run length compression. RLE is a pretty standard compression
algorithm,
>> but what is scan line compression? (I'd like to decide which compression
>> will be better for the images in my resources, but I'd rather not have to
>> make that decision by trying it out on every image. Knowing the
>compression
>> algorithm would help.)
>>
>> Thanks in advance,
>> -Bob Whiteman
>>
>> > -----Original Message-----
>> > From: David Fedor [mailto:[EMAIL PROTECTED]]
>> > Sent: Friday, September 08, 2000 4:06 PM
>> > To: Palm Developer Forum
>> > Subject: Re: m100 EFIGS oddness
>> [...]As for Security: ROM space was very tight and so they had to keep
>that
>> > application compressed in ROM, and the appropriate language of it gets
>> > decompressed and installed in RAM once you've chosen your language.
>> > Having 5 languages all available takes a good deal of memory, and
>> > there wasn't quite enough without the Welcome app doing a little
>> > compression on the Security app.
>> >
>> > -David Fedor
>> > Palm Developer Support
>>
>>
>
>
>
>
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