On Thursday 05 March 2009, James wrote:

Ideally, I'd like all the yellowed paper that forms the background of these images to turn as close to white as possible, while all the pencil text should be as close to black as possible. Can anyone point me to things I can try under gimp that will help me accomplish these aims?

If you have to work with many pages, my first idea would be to do an automatic white balance correction (Colors > Auto > White Balance). With a little luck, it'll pick the "yellow" as white and the pencil as black. If that doesn't work out as you expect, do it manually with the levels tool[1], and make use of the three eye droppers (mainly the white one) in the "All channels" section.

Getting to know the levels tool (or curves too for even more control) will help you with photos and scans anyway.

Greetings, Daniel

[1] http://docs.gimp.org/en/gimp-tool-levels.html

< snip >

I'm not any kind of gimp power user or anything--I usually just feel my way around the program and usually get it to do the fairly simple graphic manipulations I want. So far, that method has not worked well for this project. So I'd like to ask some tips here on accomplishing the goal I'm after. Ideally, I'd like all the yellowed paper that forms the background of these images to turn as close to white as possible, while all the pencil text should be as close to black as possible. Can anyone point me to things I can try under gimp that will help me accomplish these aims?

I think there was a video covering this sort of thing on www.meetthegimp.org some months ago, but I am not absolutely sure.

Norman

On Thu, Mar 5, 2009 at 11:34 PM, James wrote:

As further information on my project, I mention yellowing of the paper. It would probably be more accurate to call it "browning" since, in some instances, its shade can approach the same intensity of light pencil markings.

You can also try to decompose the image into different colorspace components (Colors -> Components -> Decompose) Start with LAB, but try the others too. It will give you grayscale layers which might be easier to use the level tools on.

Do you have a sample image?

You might find it worth trying 'digikam' first if you have many pages to process and are more interested in legibility than final aesthetic appearance.

I've used it a lot for "restoring" old documents: Image=>Edit=>Color=>Auto-correction offers you 4 types of correction. One or other of these will usually improve matters considerably. I use gimp only for the occasionally necessary final tweak or particularly difficult document.

Doug

James wrote:

Hi. I have an elderly friend whose father kept a diary during WW2. The diary is written in pencil on poor quality paper that has yellowed considerably with age. The text is still pretty legible but as time passes it will become less so. I decided I could photograph pages of the diary and enhance them using Gimp. The final result should be something that can be printed out on a computer printer, i.e., greyscale/b&w. I took the photos in color, thinking I'd have more manipulation options, then could make the images greyscale.

I'm not any kind of gimp power user or anything--I usually just feel my way around the program and usually get it to do the fairly simple graphic manipulations I want. So far, that method has not worked well for this project. So I'd like to ask some tips here on accomplishing the goal I'm after. Ideally, I'd like all the yellowed paper that forms the background of these images to turn as close to white as possible, while all the pencil text should be as close to black as possible. Can anyone point me to things I can try under gimp that will help me accomplish these aims?

Hi. I have an elderly friend whose father kept a diary during WW2. The diary
is written in pencil on poor quality paper that has yellowed considerably with
age. The text is still pretty legible but as time passes it will become less
so. I decided I could photograph pages of the diary and enhance them using
Gimp. The final result should be something that can be printed out on a
computer printer, i.e., greyscale/b&w. I took the photos in color, thinking
I'd have more manipulation options, then could make the images greyscale.

I'm not any kind of gimp power user or anything--I usually just feel my way
around the program and usually get it to do the fairly simple graphic manipulations I want. So far, that method has not worked well for this project. So I'd like to ask some tips here on accomplishing the goal

Thanks

I'm
after. Ideally, I'd like all the yellowed paper that forms the background of
these images to turn as close to white as possible, while all the pencil text
should be as close to black as possible. Can anyone point me to things I can
try under gimp that will help me accomplish these aims?

Cool! I'm sure these tips can help everyone. I will try to improve my writing skills with them, because now I am a terrible writer. When I need to write a student paper, I order it here - https://www.trustmypaper.com/ . I love the quality and price tag of this service.

If you have to work with many pages, my first idea would be to do an automatic
white balance correction (Colors > Auto > White Balance). With a little
luck, it'll pick the "yellow" as white and the pencil as black. If that
doesn't work out as you expect, do it manually with the levels tool[1], and
make use of the three eye droppers (mainly the white one) in the "All channels" section.

Getting to know the levels tool (or curves too for even more control) will
help you with photos and scans anyway.

Greetings, Daniel

[1] http://docs.gimp.org/en/gimp-tool-levels.html

Guys, thanks for the help!