> I know a jpeg is lossy but I did say compressed to a SUITABLE size. > That size will depend on requirements. Compressing once at a high > quality level makes very little, if no difference, to the published > result. What I was trying to clarify is that a Jpeg does not exist > independently of a Tiff file. It is a Tiff file compressed.
Mhm, I guess this all leads just to more confusion. Here is a good resource explaining JPG: http://dx.sheridan.com/advisor/jpeg_file.html and this explains TIFF files: http://dx.sheridan.com/advisor/tiff_file.html The important part: > TIFF files can be compressed by using an LZW lossless compression > approach or JPEG lossy compression. Technically TIFF files are just "envelopes" and can hold all kind of data (there are more than 50 different ways to create a TIFF file). Even RAW files are normally just TIFF files using the TIFF envelope and their internal raw dump as data section. If the data section format inside the TIFF envelope is not known (read: non described by the vendor), it can not be read by programs like Photoshop. For example a Nikon NEF file can be renamed to TIFF and you can see the embedded thumbnail with every TIFF viewer, but you can not decode the data section, because Nikon made a secret out of it (which got reverse engineered by lots of programmers). Hope this clears up a bit of the confusion. Juergen =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
