Re: [Openexr-user] Does OpenEXR Handle Large Images

[Michael Wolf]

On Tue, 15 Feb 2011 20:38:10 +0100, Ben Thompson <address@hidden> 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

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