newbie

[degarb]

I just bought a new sony cybershot 350--14 mega pixels- for $179 at sears. I don't like that the colors are less vivid than my gateway dc t50.

So I googled 'program to increase jpg saturation' and stumbled over here just a few minutes ago. The project looks promising (windows xp here) but perhaps over the head of an amateur like me. It looks like even the descriptions of the offerings are written for photo experts and programmers.

First: what is the best batch saturation tool for me? ( I only want one task--color saturation-- and to try it quickly, for now. I see one thread, but no mention of platform or downloaded tools.)

Secondly: what is a good photography discussion forum that isn't too deep? ( I will read once every 3 months when grass isn't too high on a Saturday.)

Thanks.

[snibgo]

ImageMagick is aimed at people who aren't afraid of the command line. For example, to increase the saturation of a number of JPEGs (in Windows):

Code: Select all

md \moresat
cd \moresat
copy \mypictures\*.jpg .
mogrify -modulate 100,180,100 *.jpg

In the above, "180" gives a massive increase, just to be obvious. You probably need something more like "120". (Note: this makes copies, and changes those. Always backup your originals, and never ever change them.)

I founded a non-technical photo forum many years ago: http://photo.net/philosophy-of-photography-forum/ (but no longer administer it). Other forums there address technical issues.

[degarb]

I am a dos era user. So what do I need to download to do this on xp?

[snibgo]

Follow the instructions at http://www.imagemagick.org/script/binar ... hp#windows

You just download and run an installation file.

[Bonzo]

When you have Imagemagick installed - do not forget ghostscript as well if you are working with text - this may be of help:
http://www.rubblewebs.co.uk/imagemagick ... indows.php

[degarb]

ImageMagick is aimed at people who aren't afraid of the command line. For example, to increase the saturation of a number of JPEGs (in Windows):

Code: Select all

md \moresat
cd \moresat
copy \mypictures\*.jpg .
mogrify -modulate 100,180,100 *.jpg

In the above, "180" gives a massive increase, just to be obvious. You probably need something more like "120". (Note: this makes copies, and changes those. Always backup your originals, and never ever change them.)

I founded a non-technical photo forum many years ago: http://photo.net/philosophy-of-photography-forum/ (but no longer administer it). Other forums there address technical issues.

Thanks, I just took the plunge and installed and created a bat file. I like the look of the 180. But, what is the artifact that will be added to the photos with color saturating like this?

[degarb]

also, what would the proper "for in " dos bat file be, to be recursive?

[snibgo]

I like the look of the 180. But, what is the artifact that will be added to the photos with color saturating like this?

I'm not sure I understand the question. The command will increase colour saturation: dull colours will become more intense, without changing hue or lightness much. But greater values will remove darkness and lightness from all colours except pure black and white. Try "5000" to max-out saturations, losing information that can't be restored.

also, what would the proper "for in " dos bat file be, to be recursive?

See DOS domentation such as "help for". You might use FOR /D %%f in (*) DO ... to walk through directory names, or FOR /R %%f in (*.jpg) DO ... to walk through jpeg files. In either case, replace the appropriate part of my commands.

[fmw42]

also, what would the proper "for in " dos bat file be, to be recursive?

See the following as it may help. http://www.imagemagick.org/Usage/windows/

Also for newbies, see all the pages at http://www.imagemagick.org/Usage/

[degarb]

One concern is the saturated jpg's are smaller files than the originals. I assume that is because the camera is compressing the jpgs to a higher quality value than mogrify.

If this is the case, (I would like to know what the quality % is, since I don't like qualities below 92-94 percent, based on my map scanning in past.) is there some command line control of the jpg quality?

[fmw42]

One concern is the saturated jpg's are smaller files than the originals. I assume that is because the camera is compressing the jpgs to a higher quality value than mogrify.

If this is the case, (I would like to know what the quality % is, since I don't like qualities below 92-94 percent, based on my map scanning in past.) is there some command line control of the jpg quality?

I suspect each systems measure of quality may be different. Nevertheless, IM default for -quality in jpgs is 85.

see -quality at http://www.imagemagick.org/script/comma ... ptions.php in particular at http://www.imagemagick.org/script/comma ... hp#quality

[snibgo]

The best available quality for jpegs come from, I think, "-quality 100 -sampling-factor 1x1".

But this can't replace quality that has already been lost, and may give a larger file than is justified. I never use jpegs for anything other than final results, because every conversion can lose information.

[degarb]

The 85 quality is a bit low, I suspect.

My reasoning: it is like making an mp3 of an mp3. So you are getting 85% of an 85% image = .85 x .85 = 72.25% image quality .... Or am I wrong?

Just testing and looks like, to keep roughly the same size, the compression of mogrify should be between 96 and 97 percent. (And, that 3 to 4 percent loss from the original is probably somewhat significant, but not in real world terms--I just am not sure. I base this on a map scan I did a few years ago and testing jpg compression from 92 percent (which was maximum compression acceptable for reading the street names) to 100 percent; even at 99 or 97 percent, the loss was startling noticeable. I think, based on size to quality ratio, I chose the 94% jpg to scan the maps.)

I am leaning toward 'mogrify -modulate 100,136,100 -quality 97 colorenh\*.jpg' for the bat file without the for in routine.

I did wrestle with putting the -quality 97 after the *.jpg. The placement of the switch at end, nullifies the switches use by mogrify.

This is an exciting tool. I will see what other improvements it can do next weekend. Any one with, any other suggested improvements?

[snibgo]

The default jpeg quality setting now seems to be "95". I thought it was "85". Perhaps it has changed, or I have been wrong.

The quality number and file size may have little to do with real life:

Code: Select all

convert in.jpg -quality 100 -sampling-factor 1x1 out.jpg

can increase both quality setting (see "identify -verbose") and filesize without adding meaningful quality.

[fmw42]

all options in convert or mogrify should be before the output