From: Spartanicus said:
Pointless if most of the information will be thrown away as is common
with web images.
It is not pointless if you do not know what use you will make of the pic or
if you might want to print later. And it is not pointless if they are to be
given later to someone else to prepare - who would not want better orig pics
to work with? And it is not pointless as general advice knowing nothing
about how what camera does what job in compressing things, any camera will
do less damage the less it goes to work with its hatchet on the information.
Expensive advice, and unnecessary, Photoshop uses the same jpeg
algorithms as other software.
I am sure there is a lot of good software besides PS. If it is really true
that there is a lot of cheap software that does this job just as well, then
fine. Suck it and see, I would not tend to be too trusting beforehand
though... But I don't think (not quite on your point, I realise) the same
can be said for resizing (px size, height, width wise) algorithms in
different software. In PS it is very good in quality (using the bicubic,
which was slow on old computers but lightening on modern)
Resizing is performed on uncompressed 24 bit bitmaps, the above advice
would therefore result in extra information loss.
Oli was saying something on this bit, I am not fully with you. Could you
spell out this argument please.
If you resize first (meaning changing a 1150px sq pic to 500px sq) you get
a smaller pic with many pixels discarded and adjusted depending on the
algorithm used. If the file size resulting is too big, you hit it with a jpg
compression technology and you lose more info. Either way, you lose info
twice. What is it about the order I suggested that seems wrong to you?
I do it in one or the other order at different times. I have only an
intuitive idea of which order is "best" and in truth, it is hard to tell the
difference between a pic prepared one way rather than another! I was
figuring that it was best for the more complex algorithm of jpg compression
(holding the px-size) was best done on more good quality info. But I do not
know for sure. I am yet to see that I gave Jim any bad (rather than
unnecessary) advice.
dorayme