The Marking Extraction Pack is an addon to Cartograph G In order to use it, extract all files to the folder with Cartograph G files. The Marking Extraction Pack can be used to render all chunks in a marked rectangle. You will need an offset file of the world you wish to mark chunks of, this can be generated by checking "Generate offset file" on the main Cartograph G interface by clicking "Advanced options" and then "Advanced location settings" Only 2D maps can be marked, and the post processor is disabled. When the rendering is completed, locate the generated image (it has "offset-canvas" in its filename) and open it in image manipulation software. Mark the parts that you want to render with black dots, lines or rectangles (the end result will be a rectangle including all markings) and save the file. You can reuse the same offset-canvas file, but the image does not repair itself if you remove markings. Then you can drag-drop the previously generated offset file (named <world_name>Offset.txt) to the binary called "Cartograph_G_Marking_Extractor.exe", you can also instead use the command line. The offset file will now be updated to include the X and Z coordinates that include all marks. In order to use this updated offset file, select select "From marked offset file" in the "Chunks to render" dropdown box at the Advanced Location Settings. The offset file is specific to the given world name (it searches for <world_name>Offset.txt), so if you want to use multiple different marked offset files for one world you can change the name. If you still have "Generate offset file" checked you should uncheck it, otherwise your marked offset file will be overwritten with an empty one. The other settings do not matter, you can render the partial map in any view mode with any options on any orientation.
grzegorj