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[The Old Man]

I have a question relating to image compression when using and uploading .jpeg compressed images. I use Coppermine and ImageMagik.

I scanned some photo's as .bmp's, then saved them with 10% quality reduction (90%) and uploaded them into Coppermine.
I was thinking later about the Config settings in Coppermine which state:

Files and thumbnails settings  
Quality for JPEG files:  80

Does this mean that after uploading the photo's that have lost 10% of quality, that Coppermine will then reduce them by a further 20%? Or does this relate to the creation of thumbnails?

Thanks!
Graham.

[Casper]

It relates to the thumbs and intermediate (if created).  The originals are untouched.

[The Old Man]

Thank you, much apprecaited!

[Joachim Müller]

jpeg compression is not lossless btw; compressing a jpeg image twice or more always means loss of picture data.
Mentioning BMP in this case is irrelevant, as BMP is an uncompressed format that usually produces large files and is hardly fit for being used on the internet.

GauGau

[The Old Man]

Thanks for the info.  I'm aware that .bmp are not suitable for the interent, its .jpegs that I'm using and wanted to make sure that the quality of my uploaded photo's even with 10% loss compression were not being further compressed. I only mentioned .bmp because that's the original format from when I scanned them. Everytime you re-save a .jpeg it loses quality which of course only makes it suitable for the final image for internet use.