PhotoBanter.com - View Single Post - Compression in JPEG files in digital cameras

**Ron Hunter** · August 19th 07, 09:34 AM posted to rec.photo.digital,uk.rec.photo.misc

wrote:
I need some help in explaining the JPEG compression feature in digital
cameras. My camera (which likely is similar to most others) has the
feature to compress the photo JPEG files in the storage card. It also
has the choice to have different pixel sizes (example: 3000x2250,
2000x1500, 1024x768, etc). What is the difference of the above two
features? If you store a 3000x2250 pixel data in compressed mode,
does it loose its quality? Can it be re-instated to full uncompressed
size without loosing photo quality?. When I compressed the data, it
will fit more pictures in a single storage card. But, is it the same
if I choose 2000x1500 pixel and no compression instead?
Thanks for info.

Most P&S cameras produce .jpg picture files, which are ALWAYS compressed
to some degree, and they also do lose some picture information, which is
why the JPEG compression system is labeled 'lossy'. In the practical
sense, if the camera has multiple compression settings, select the
lowest compression value, usually expressed as 'fine', or 'super fine',
and the highest resolution setting. Memory cards are VERY cheap these
days, so there is really no reason to skimp on resolution, or compress
excessively.