Ok, something to keep in mind with CS5 photoshop any change of its brightness and or contrast usually is considered a permanent change.
However if your image is a camera raw file (straight from the camera in its native raw format) a tiff or a jpg, you can and should open the file in Adobe Camera Raw (ACR) as any edits done in ACR are non-destructible in that any changes made can be changed or reset at any later time in the future as it does not alter the image it self, but applies the edits to the metadata.
That said, it means in order for a program to see those changes it needs the ability to read the metadata, which not all programs can do.
In ACR you will find a contrast slider, by decreasing the contrast the image will become lighter. You can also increase the highlights or whites and you can decrease the shadows or blacks. This effectively is similar to lowering the contrast, but because it is an additional step, you can do all three sliders effectively reducing the contrast even further than you would be moving the contrast slider by itself.
Since this is a metadata alteration, this change you made can be applied to a folder full of images that are the same formats I mentioned above, or you can select a group of images in bridge and apply to just the selected group.
At any time in the future you can remove the edits should you need to use the original image once again.
Thank you for the information.
Perhaps I was not clear enough that I am talking about pdf files. I am not sure how what you say applies.
I tried to open a pdf file using Photoshop Raw. Is that what you are talking about? It is a 20-page document but all that appeared on the screen is a dark rectangle. It doesn't seem like something that can be worked with.
Any additional insights about lightening or removing images and graphics in pdf files would be appreciated.
OK, I think I was under the assumption that you wanted to create a pdf with lighter version of the images to print later.
When you place a pdf file in photoshop, it is rendered, therefore the entire file/page would be editable as you would any other image.
Take a look at the adjustment layers. You will find one that is just for brightness/contrast. That will do what you want and will affect all layers below it unless you clip it to the next layer.
You can find the adjustment layers in the layers menu and it is also located at the bottom of the layers panel. Just hover over each icon and it will tell you what they mean. Click on the icon will bring up a menu of all the adjustment layer commands that are available.
I was about to ask how the pdfs were produced, scanned pages, etc. but after googling Leanprint I was suprised to learn that this is an Adobe product.
You should try the Adobe Leanprint forum: Adobe LeanPrint
Thank you, Bo.
Unfortunately, Leanprint is somewhat limited in what it can do. I am looking for additional ways to cut back on wasteful and unattractive (in black and white) use of toner.
This information gives me something to start with and is just what I was asking for.