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More questions which I can't find the answer for on the WWW... [img]/infopop/emoticons/icon_frown.gif[/img]
If I keep manipulating and re-exporting an uncompressed TIFF file between different applications - will I get a degradation in image quality (even a theoretical one?). Can it be done indefinitely?
Oh, yes, the most important thing - I would not be re-scaling, altering the resolution or the color depth of the image.
Anyone?
Risto
risto@ristoklint.com
Visit my web site!
More questions which I can't find the answer for on the WWW... [img]/infopop/emoticons/icon_frown.gif[/img]
If I keep manipulating and re-exporting an uncompressed TIFF file between different applications - will I get a degradation in image quality (even a theoretical one?). Can it be done indefinitely?
Oh, yes, the most important thing - I would not be re-scaling, altering the resolution or the color depth of the image.
Anyone?
Risto
risto@ristoklint.com
Visit my web site!
Yes. This applies to BMPs and PNGs as well because they use a non-lossy compression. Avoid JPEGs. GIFs are OK so long as the original was a GIF (i.e. only 256 colours).
Regards - Sean
Thank you, Sean!
I'm so happy I could cry!
Risto
risto@ristoklint.com
Visit my web site!
Risto, here's an added note (If you don't have Photoshop or some other bitmap editing program).
I had a tiff file of a logo. It came from a scan and on close inspection the anti-aliasing on some of the text was too "jagged". I used S-Spline (as mentioned by Klaus Norby in the New Gear forum) on it to sharpen things up and increase the resolution. It really did the trick.
Now I have a hi-res bitmap that can be used as a "Master" file in other applications as neeed.
I've been asked to clarify my short answer.
Assuming there's no reduction in colour depth or re-sizing, importing and exporting formats that are uncompressed or use lossless compression should cause no degradation to the image. The only widely used lossy format I'm aware of is JPEG, but note that BMPs and TIFs can also use JPEG compression. PNGs, GIFs and uncompressed BMPs and TIFs are safe, as are compressed BMPs and TIFs that use RLE or LZW compression. Converting a 256 colour image to 24-bit is safe, but converting it back again may not be. Transferring bitmaps via the clipboard is usually safe if you've got 24-bit VGA but could be temperamental if you're using anything less (it's safe if you can opt for a Device Independent Bitmap).
Regards - Sean