I have a few hundred images of 30000 x 10000 pixels in size. Each image has lots of text (rendered as pixels) on it. I'd like to translate all text to another language. I speak both languages, and it's fine for me to translate each phrase manually. I need an image editor which can open these images quickly (faster than Inkscape, which needs about 60 seconds to open such an image), lets me zoom and rotate by 90 degrees, lets me erase (i.e. change the color of a selected rectangle to solid white), lets me add text, and lets me save the file as quickly as possible. I'd like to minimize the time I have to wait for the software to load, render and save images. Which is the best program for that on Windows? On Linux?
This is my fallback plan: Use David's Batch Processor to convert all input images to XCF (GIMP's native file format; it will be about 10 MB for an image of mine), and do all the manual work in GIMP. Loading such an image takes about 10 seconds in GIMP 2.8 (on the same machine where Inkscape needs 60 seconds), and saving it takes only 1 second.
http://iipimage.sourceforge.net/ might help you. It is a web server driven viewer for ultra high-resolution images, it works like google maps. Pre-processing (e.g. rotation) can be done using bash+imagemagick.