Uncompressed and Jpeg?

[777heavy]

Hi,
What is the difference between a jpeg image and an umcompressed image?
Are there any advantages using uncompressed over Jpeg?
Which out of the 2 are better?
I am reffering to the modes of the FZ 20
Thanks for all your help.

[Axle]

Okay:

Uncompressed: or the RAW image format is larger in storage space needed to keep the image on the card/camera. This is good if you're getting prints of your digital work.

JPEG (JPG): is a compressed image format, if you're just posting images on the Internet or for long term storage on your computer. Also since they are compressed they take up less space than a RAW image.

[SmartWombat]

Uncompressed retains all the original image detail.
JPEG compression loses image detail and with each editing and re-saving loses more and more.

There are compression techniques that do not lose detail - surprise, they're called lossless
But typically you only get 3:1 compression which isn't enough to make today's megapixel images practical.

So although it's compressed, the TIFF doesn't suffer loss as it is uncompressed and you get the original back.


Which is better?
Pass. Disk and memory card use, quality (that you'll possibly not notice), what will determine which is best for you depends on what you use the images for.

[Chunk]

It's been a while since I have recommended scantips.com as a source of info but the info there is still as valuable as it ever was.
http://www.scantips.com/basics09.html
Check the links at the bottom for more discussion.

[another view]

Some cameras can shoot in TIFF mode but I don't see a real advantage to it. I've shot in jpeg, then done some editing to the image - and then saved to TIFF. The first "save" at time of capture isn't really going to hurt the image much. I've made large prints with this technique and they look great.

RAW is also not compressed (I think Nikon's NEF has a compressed RAW format though) but RAW has other benefits as well. I don't think it's always necessary to use RAW though - use the right tool for the job and you'll save a lot of time but still get great results.

[Trevor Ash]

One advantage for shooting RAW/TIFF in some cameras is that when shooting in that mode the images are 16 bit instead of 8 bit (well, 14 bits of color info maybe). This is helpful in later stages sometimes....but I admit not necessary for the things I usually do.

[trog100]

i think this is more a "purist" thing.. if u follow the image quality being paramount concept.. logic says that u cant accept any image degradation that can be avoided.. hence such folks cant tolerate the inevitable image quality loss thats come with a jpeg..

storage is less of a problem than it was a few years back.. hard drives are huge.. so are memory cards relatively speaking.. most folks now have broadband so even the accepted size of web based images can be larger..

so there is less need for heavily compressed jpegs.. again a few years back for practial reasons jpegs tended to be more heavily compressed than they are now.. cameras now tend to offer several options as to how much u compress the jpeg image.. the more u compress.. the more compression artifacts will show up..

convenience usually wins out.. jpegs are convenient.. assuming u dont compress them too much the loss is not noticable to most folks.. to satisfy those that arnt happy with any loss.. we have the lossless tiff.. big image size and slower to save.. but its there if u feel u need it.. then we have raw.. i think the idea behind raw is to keep camera proccessing down to a minimum and let the picture taker feel he has more control over the finished product.

also in-camera jpeg compression algorithms do seem to have improved noticably over the last few years.. they have basically become quite good at bunging a gallon sized image into a pint sized pot.. he he

trog100