I have 12 PDFs of pictures of a map. I want to use GIMP or any other program to stitch the pictures together.

When I open the PDFs in GIMP, the pictures have bad enough clarity that I cannot read the words in the pictures anymore. I need to be able to read the words in the pictures so that the map is usable.

I want to bring the PDFs into GIMP, or another program that I can use in Linux, to stitch them together. I want the clarity of the pictures to be high quality and file size is not an issue.

How do I do this?

As long as the original PDFs have clear letters, you should be able to do it with the right import settings. Take a look at the dialog box I've screenshotted. You need to use large enough resolution numbers. You may also want to check the Use Anti-aliasing checkbox.

Just note too that as a basic matter, GIMP cannot edit or concatenate what I'd call a 'clean' or 'true' PDF. Such PDFs contain vector graphics (geometric instructions on how to draw the graphics and text). To important these into GIMP, it has to convert the vector graphics into raster graphics (basically bitmaps). That conversion will cause at least a little quality loss unless done at exactly the resolution needed for final use. But done properly, the loss should be minimal.

There are other PDFs that are basically already wrappers for raster graphics. Somewhat more quality loss is basically inevitable, but if done right, should be minimal.

I have 12 PDFs of pictures of a map. I want to use GIMP or any other program to stitch the pictures together.

When I open the PDFs in GIMP, the pictures have bad enough clarity that I cannot read the words in the pictures anymore. I need to be able to read the words in the pictures so that the map is usable.

I want to bring the PDFs into GIMP, or another program that I can use in Linux, to stitch them together. I want the clarity of the pictures to be high quality and file size is not an issue.

How do I do this?

Bruce

Typically a PDF that is a wrapper for a graphic uses 300 pixels-per-inch (ppi) for the graphic. But not always try and see.

Gimp default for importing a PDF is 100 ppi see: example 1:

Increase that value to 300 ppi for better but larger sized image in pixels. Gimp is a raster editor and works in pixels. example 2:

When it comes to stitching together, 12 images might be a chore, depends on the image sizes, lots of layers = large use of computer memory. Try stitching together images of separate rows, then use those images to combine as columns.

Alternatives to Gimp: If there are decent overlaps there is Hugin and for those very large mosaics, Nip2 (not recommended for beginners). I believe the MS one that is free is not bad, never used it.

rich: www.gimp-forum.net