On Tue, 15 Feb 2011 20:38:10 +0100, Ben Thompson <[email protected]> wrote:
Hello Everyone,
Hello Ben,
I'm trying to create large HDR image files. I have been using applications that write both .hdr and .exr; I have been using the former for no special reason. However, it seems that the applications generate invalid .hdr files when the image is more than 32767 pixels wide. I believe this is because they write RLE-compressed .hdr and RLE is not supported for images this wide. I'd like to know if .exr files have any limits on image size both in the case of no compression and compression with each/any of the available compression methods. I know of RLE, Zip (with and without multi-scanline, PIZ and PXR24.
The largest file I've created is a tiled EXR at 86,400 x 43,200 pixels, half, ZIP compressed, 3.9GB. So far the only major limitation I've encountered is the C++ i/o library on windows capping at 2GB, which is why I have a patch for windows that uses OS specific i/o routines. (it works as expected out of the box on OSX, the only other platform we support so far). Basically, pointers into the file are 64-bit and dimensions 32-bit integer. I suspect those to be the only limits. I can send you the patch if you need it. Cheers, Mike -- db&w Bornemann und Wolf GbR Seyfferstr. 34 70197 Stuttgart Deutschland [email protected] http://www.db-w.com tel: +49 (711) 664 525-3 fax: +49 (711) 664 525-1 mob: +49 (173) 66 37 652 icq: 252887990 skype: lupus_lux msn: [email protected] _______________________________________________ Openexr-user mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/openexr-user
