Comments on: Recoloring Or Modifying GeoTiff Images

By: sim

sim — Fri, 07 Dec 2007 04:06:48 +0000

Along the same lines, if you have multiple rasters uniformly indexed and software like Arcview GIS, using a simple script you can easily switch on and off one or more colors/information classes. I’ve shown the example here http://gis-lab.info/qa/trlegend.html, it is in Russian, but the idea should be clear. We use this approach to work with hundreds of raster maps simultaneously.

By: geofumadas

geofumadas — Fri, 07 Dec 2007 00:15:42 +0000

Thanks for the info, what about manage raster to vector?

By: Leszek Pawlowicz

Leszek Pawlowicz — Thu, 06 Dec 2007 19:51:50 +0000

Haven’t played with The GIMP for a while, so I downloaded it and took a look. While it will let you look at the indexed color table, you can’t modify it directly, and you can’t colorize an indexed color image, only an RGB one. There may be another way to do it, but the GIMP’s interface is still as painful and non-intuitive as I remember it, and I don’t feel like banging my way through it. And while it’s not as big a memory hog as Paint.Net, it’s close, and it’s very slow with large images. I’m not a huge fan of Photoshop either, as I don’t really care for its interface, but it is faster, less memory-intensive, and offers more features than either The GIMP or Paint.Net.

Paintshop Pro also lets you modify the color table for indexed color images. While it’s not free, it’s cheaper than the current version of Photoshop Elements, and is more powerful.

By: Leszek Pawlowicz

Leszek Pawlowicz — Thu, 06 Dec 2007 19:33:24 +0000

Paint.Net does have a recolor function, but it’s manual - you have to paint the recoloring over the entire image with a brush, and that can take a while. There’s no universal re-coloring, and no support for indexed color. Paint.Net is also an incredible memory hog; I have a standard USGS 24K topo map loaded in it now, and it’s using almost 400 MB of memory.

By: Matthew Winslett

Matthew Winslett — Thu, 06 Dec 2007 18:35:17 +0000

There is also the GIMP, which is a free image editor very similar to Photoshop. The UI is different, but I believe that it does many of the same things as Photoshop

By: Matt Fox

Matt Fox — Thu, 06 Dec 2007 18:06:48 +0000

Thanks for all the great tools and tips. Paint.net is a great freeware photogshop clone that I’m pretty sure also has color picking ability.

http://www.getpaint.net/

By: Remote Sensing Tools

Remote Sensing Tools — Thu, 06 Dec 2007 15:11:51 +0000

Geotiff and Photoshop Tutorial by Leszek Pawlowicz…

Leszek Pawlowicz updates this morning with a tutorial for recoloring or modifying Geotiff images in Photoshop, with USGS topo maps and LibgeoGUI.
……