Re: [Openexr-devel] OpenEXR vs Raw images

[Billy Biggs]

nkb (address@hidden):

> Does storing my images in OpenEXR present any advantages over storing
> my images as Raw images (such as the CRW format from Canon digtial
> camera)?

  The difference would just be in terms of what applications can read
the files.

> I did a simple comparision. In terms of file size, for the same image,
> canon crw file size (in my example) is 4.7MB while openexr format with
> piz compression yields a result of 12.8MB.

  Canon CRW format uses 'lossless JPEG' which is pretty complicated and
less general than what you see in OpenEXR, I would expect it to compress
better for pictures from your camera.

> Further, in terms of being able to control the exposure levels, tuning
> the images with various details, crw format seems to have more
> controls and I'm able to get the right image out of a CRW file.(I use
> photoshop CS) So what am I missing here? Thanks.

  This has nothing to do with the file format, this is just the
capabilities of the software.  The CRW format itself does not have
'controls', the software that manipulates it does.

  -Billy