I have a few questions about dealing with layers.

Is there an easy way to select a rectangular area and then move (cut/paste) it to the same location on a different layer? When I try normal cut & paste, there doesn't seem to be an obvious way to preserve the exact location.

Is there an easy way to save each layer to separate files?

What I'm trying to do is take monochrome (bilevel) scanned images from a document that originally had some black text and line art and a small amount of text in another color (typically red), select the part that should be red, move it to a different layer, and save the two layers as separate TIFF G4 files.

Perhaps there's an easier way to do this than using layers, but I specifically don't want to have to make two copies of the original file, independently select the area in both, and clear the inside of the area in one file and the outside in another.

A related problem I'd like to solve is taking a bilevel scanned image, selecting a rectangular area that contains a dithered photo, clearing the photo, and writing the coordinates of the selection to a file or to standard out for use in a later processing stage.

The motivation of all this is the use of a high-speed duplex scanner (Ricoh IS520), which ONLY supports bilevel, to produce archival PDF files of documents that may have some colored text or some photos. In the case of photos, the plan is to separately scan those pages on a color or greyscale scanner, and merge the photos into the PDF using a separate images-to-PDF program I'm currently developing. But I'm only trying to write a command-line/script interface for my program, and would prefer to somehow leveage GIMP to handle the user interface needed to select and manipulate the necessary region selections.

I assume that if there's no easy built-in way to do what I want, that it should be possible to write some script-fu to do it? I read the Script-Fu chapters of the GIMP manual, and I've done some emacs-lisp hacking in the past, so the basic concepts are not too foreign, but it's still not obvious how to do the things I desire.

Thanks for any suggestions! Eric

David Burren wrote:

Surely something like this would work? - Duplicate the layer
- Select the appropriate area
- With one layer active, clear the selected area - Switch to the other layer, invert the selection, and again clear

OK, I'll try that. It sounds like it will do what I need, which is satisfactory for now.

However, I'd ultimately like to come up with an easier way for the user to do that, since it will need to be done hundreds of times in a single scanned document. Can anyone offer a hint as to how to write a macro that I can attach to a menu item or hot key? I've already RTFM, but I'm somewhat stumped.

Thanks very much! Eric

David Burren wrote:

Surely something like this would work? - Duplicate the layer
- Select the appropriate area
- With one layer active, clear the selected area - Switch to the other layer, invert the selection, and again clear

I wrote:

OK, I'll try that. It sounds like it will do what I need, which is satisfactory for now.

On second thought, it's not quite what I want, though it may be a step in the right direction. The problem is that there are going to be multiple rectangular selections in the same page that I want to move from the original layer into a new layer. And I want them to wind up in a *single* new layer, not a bunch of them. I guess that if each selection wound up in a distinct new layer, that I could hide the original layer then use Merge Visible Layers, but by the time all is said and done this will be quite a cumbersome process.

And once I get my selections into the second layer, I still need to figure out how to save the two layers into independent TIFF files.

Thanks, Eric

"David Millet" wrote:

a couple of thoughts:
1) if you want to save a layer separately, the easiest way i know of to do that is to click on the layer in the layers, channels, and paths dialoge, drag it to the toolbar, and it will create a new image with just that layer.

Cool!

2) to move the different colored text to a different layer and keep it in the same spot, i would do the following: 1. use the select contiguous regions tool, select the red letters 2. hit ctrl-c to copy, then ctrl-k to clear whats in the selection 3. create a new layer
4. right click on the image and choose Edit>Paste Into

That seems like the best approach so far.

Thanks! Eric