2007.04.05 20:04 "Re: [Tiff] Floating point RGBA", by Toby Thain
On 5-Apr-07, at 4:58 PM, Craig Bruce wrote:
That seems like a very strange combination. If I remember correctly, packbits is a byte-based RLE scheme. Applied to floating point data, compression ought to be very inefficient.
It may be a sensible option if the image has significant regions of solid black. The IEEE floating-point representation of 0.0 is: 0x00, 0x00, 0x00, 0x00 (in either endian).
Dictionary compressors are much more likely to win, overall. RLE does seem an odd choice, regardless of the actual data characteristics.
--Toby
>
> --------------------------+----------------------
> +--------------------------
Dr. Craig S. Bruce | Ph 819-771-8303 x205 | CubeWerx Inc.
Senior Software Developer | Fax 819-771-8388 | Gatineau, Québec, Canada
> csbruce@cubewerx.com | http://csbruce.com/ | http://
> www.cubewerx.com/
> --------------------------+----------------------
> +--------------------------
"Hard work may not kill you, but why take chances?"
> _______________________________________________
> Tiff mailing list: Tiff@lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/tiff
> http://www.remotesensing.org/libtiff/