Saving images

Can somebody kindly help me with this one?

With ACDSee v3.1 I have the following options under sub-heading 'Encoding'
when I save an editied image: (a) Progressive or (b) Optimise Huffman Codes.

I also use PaintShop Pro v. 4.14SE, where the save options include (a)
Progressive encoding or (b) Standard.

My problem with these two programs is that I really have no idea which of
the options I should be using, and the programs help doesn't explain it at
all.

Finally, I have problems sometimes where I cannot access an image at all
because I get a window saying can't open image (I think because somehow it
has become a read only file). I really cannot understand how and image
(which admittedly may have been copied around from folder to folder) can
becone read-only.

Many thanks for any help on these problems.

John

In message , John Lee
writes
Can somebody kindly help me with this one?

With ACDSee v3.1 I have the following options under sub-heading 'Encoding'
when I save an editied image: (a) Progressive or (b) Optimise Huffman Codes.

I also use PaintShop Pro v. 4.14SE, where the save options include (a)
Progressive encoding or (b) Standard.

My problem with these two programs is that I really have no idea which of
the options I should be using, and the programs help doesn't explain it at
all.

I'm sure a Google will get you some info.

AIUI, progressive encoding is what is used on some images on the web,
where you get a poor quality image first, followed by the better quality
one a little later.

The Huffman codes bit I think just refers to the standard compression
method - go for the standard/Huffman option unless you need the
progressive bit.

Finally, I have problems sometimes where I cannot access an image at all
because I get a window saying can't open image (I think because somehow it
has become a read only file). I really cannot understand how and image
(which admittedly may have been copied around from folder to folder) can
becone read-only.

What OS and could it have been copied from CDR at some point. On CDR,
file are of course read only, in pre Winxp versions, files copied back
from CDR retain the read only attribute
--
Chris French