In some cases it is useful to output a slice of an image volume to an image file at native resolution, rather than using the mrview screenshot tool. This can also simplify ensuring that the intensity scaling between different images is consistent.

Desired features:

• Either receive a pre-cropped image from mrconvert, or user provides -coord options to specify where they want the slice(s) to be
• If input is 4D and the 4th axis has dimension 3, output as RGB colour image
• Option to manually specify minimum / maximum image intensity (useful for outputting multiple images that should have a common colour bar, even if they don't all have the same dynamic range). Otherwise the intensity range is determined from the image data.
• Output as .tga; this won't require any code dependencies, and should be supported by more software than .pgm & .ppm
• Apply colour bar mapping to image on output
• Options to flip / swap axes (maybe a comma-separated list providing x,y axes for output image as +/- input axis indices)