http://groups.google.com/groups?selm=51pest%24mv5%40bcrkh13.bnr.ca

Newsgroups: comp.os.linux.advocacy
Date: 1996/09/18

Hello, Linux folks:

I have been playing with that GIMP program and all I can say is that it rocks.

We no longer “need” an Adobe Photoshop port to Linux. GIMP has it all.

Photoshop beats GIMP basically in just the paintbox functions; there are more tools for creating original images in Photoshop. In GIMP one cannot draw lines, circles, etc. Once can only select regions of an image that will be affected by a brush. Also, Photoshop has some goodies like the creation of tesselated texture patterns, for those decadent WWW page backdrops.

That aside, GIMP matches or beats Photoshop in every respect. It has an architecture that supports external filters. A great airbrush and paint brush with a ton of useful modes, and a variable transparency level. For example, one can draw in such a way that the hue of the image is affected only, making it simple to change the color of someone's clothing, for instance.

The intelligent scissors feature is quite excellent: the operator guides the scissors by laying down control points. In between the control points, the scissors will find a path that follows a natural contour in the image. This combination of operator intervention with a sophisticated algorithm lets you easily pick out complex shapes, and either cut them out or apply filters or to them without affecting the rest of the image.

GIMP can combine images and decompose them into HSV or RGB separations, and apply a variety of standard filters to a whole image or just a selection. Easy keyboard shortcuts are provided to access the most common filters---for example to do gamma correction on an image or selection, one hits Alt-G. In fact, the entire Motif GUI is intuitive---more so than that of Photoshop.

The “clone” feature is nicely done, like in photoshop. In this mode, the user's paintbrush, rather than applying color or some other transformation, instead copies another area of the same image or another image, like a mimeograph.

One useful Photoshop feature not found in GIMP, as far as I can tell, is the ability to “lift” a selected region such that the image which remains behind is blended together to hide the hole, but given the excellence of the current release, I'm sure that this trivial addition will be found in a future version, along with a fuzzy paste. In any case, the effect can be simulated with careful blending---and GIMP does have a nice convolution tool which is used like a paintbrush. It's like a filter that you paint with. If you don't like the presets, you can enter your own convolution mask into a 5x5 grid of numbers. The filter seems to be cumulatively applied as you paint, making it intuitive to do more or less blending. In this way, it works like the airbrush rather than the regular brush, though it might be nice if the cumulative nature could be turned off, so that the filter would be applied only once per discrete stroke, like the brush.

I should also mention the multiple undo function, which is configurable in terms of how many undo operations can be done, and how much memory is used for undo. Speaking of memory, GIMP performs really well, which has a lot to do with Linux's devastatingly aggressive memory management, and also with GIMP's use of auxiliary processes which communicate image data via shared memory. This is a good idea, because the resources of a process are completely disposed of when it exists, thus the memory clean-up after a complex operation is completely assured. I checked the footprint of GIMP while editing a handful of small images (about 320x480). It was only about six megabytes. On the other hand, I recall the painfully atrocious performance of running Photoshop on a Power Macintosh 7100 with the recommended 16 megabytes of RAM with no other programs running. Constant jerkiness and spurious disk accesses spoiled that experience; GIMP is as smooth as a mug of good dark beer.

All in all, GIMP is a very excellent piece of software which adequately replaces Photoshop. The ways brush-style painting is combined with various kinds of filtering and color space constraints truly stimulates the creativity, and the intelligent selection tools make complex editing easy!

The program is freeware (except for the Motif libraries that are required to build it---but since Motif is an open standard, it may be possible, in the future, to use a freeware implementation of Motif to build programs that require the toolkit).