Saving format - which is best and why?

[Overread17 5]

When saving in JPEG (which I do for the majority of my edited RAWs) photoshop elements shows 3 differnet saving options:
Baseline (standard)
Baseline Optimized
Prograssive scan *option of 3,4,5, scans*

Up till now I have used progressive scan 5 scans - never really thinking about which is the better saving format.

So which is it?

 

[Overread17 5]

*bump*

 

[Alpha]

Objectively speaking, I dunno. I use Baseline quality 12, and only do one save to jpg from tiff or psd. Never had any problems with artifacts or compression halos. If one of the other methods is better, it hasn't produced any noticeable difference to my eyes.

 

[tirediron]

Basic rule of the thumb with .jpg is: "Bigger is better". I've not seen the 'progressive scan' option before, so I'm sure of what function that performs. I would simply save an image in each version and whichever one produced the biggest file (ie most data, least compression) would be the one I used.

 

[Helen B]

Optimized compression produces slightly smaller files than standard because the compression is tailored to the image, in simple terms. The image is analysed, then the compression table ('Huffman table') is modified to suit the image. The savings in file size are often quite small (almost always less than 10%, and usually less than 5%) and so many of us don't bother.

Progressive mode makes the image build up progressively. Try all three on an image at the same quality setting, and observe the difference in computing time (choose a large image), file size and appearance upon opening.

Best,
Helen