About GIMP
Thu, 2006-05-11 07:09 — deadfrog
I am trying the question and answers for the first time...I had to find out that one question had been answered and I just could not find the answer. Our man Matthew put me on the right track...Thank you Matthew.
GIMP Question: When saving a photo from GIMP after resizing or other work, what 'file' or format should it be saved in to make it suitable to send to most other operating systems.
Deadfrog
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JPEG
JPEG (pronounced "jay-peg") is the universal file format for publishing photographs on the web, so anybody with a web browser, regardless of operating system, should be able to view a photo in JPEG format.
It is worth remembering that JPEG is a lossy data format; i.e. some data is sacrificed to keep the file size small. Normally this loss of data is unnoticeable, but if you repeatedly edit and save an image as a JPEG file, you will get a cumulative degradation of picture quality.
So if you're going to heavily edit a file over a period of time, it is adviseable to save a master copy in a lossless format. The GIMP's default XCF format is lossless, and retains other information used while editing the image, so it's a good choice for a work in progress. The downside of XCF is that it's not an open standard, which gives the GIMP's developers the flexibility to optimise or otherwise change the format with each new release of the GIMP, but also means that no software other than the GIMP is likely to be able to read XCF files.
TIFF format is an open standard lossless compression format, but has so many variants that you can't be sure that the variant of TIFF that you save something in will be readable in whatever graphics software you may use at some point in the future. Having said that though, I've never had any trouble with TIFF files.
BMP is an uncompressed file format developed by Microsoft for use in Windows, but because of the ubiquity of Windows it is supported by practically all graphics software. For that reason it's a safe choice for archiving perfect copies of images, unless you're so bitter and twisted that you can't bring yourself to use anything developed by Microsoft. However because there is no data compression at all, and the file size is HUGE compared to the same image in JPEG format, you should never email anybody an image in BMP format. Or at least you should never email me an image in BMP format.