> What is exactly the problem with gimp's UI?

Where do I start?

  - sometimes when I start it it doesn't display toolbox
  - when I open the toolbox it is (sometimes) a vertical line of buttons (single column) instead of 5 columns that I begged it countless times to be
  - setting the size of pencil is completely unintuitive - I usually click in what appears to be input field, only to discover it is not (but instead some meter that sets size to some huge number)
  - saving the set size is something that should be done automatically, but I haven't found a convenient way to do it

And that is even without mentioning the whole Save / Export fiasco.

Note that I love Gimp and use it often, but UX is not its strong point.

> setting the size of pencil is completely unintuitive - I usually click in what appears to be input field, only to discover it is not (but instead some meter that sets size to some huge number)

It actually is an input field, but it can be interacted with in 3 ways. Clicking on the value focuses it, and allows editing by keyboard. Clicking and dragging in the bottom half of the block allows you to increase or decrease the value by dragging left or right, and the movements you make translate to relatively smaller value changes, so you can be relatively precise. Clicking and dragging in the top half of the block allows you to select a specific value by dragging, and the position of the cursor translates directly to the position of that value on the bar.

Sounds like a terrible idea, if the interaction is not discoverable. Even if it was easy to understand, you need a lot more mouse dexterity than the average user to operate something like this.

Thanks for pointing that out! I've always thought it was depending on how far from the vertical edge (i.e. current value) I click that I either get a "drag" (if clicked close enough) or a "set / drag&set" (clicked farther away). Or maybe it was just my mental model I got stuck on from some Motif (IIRC?) controls.

Actually, in Gimp 2.10.4 it now for me even changes the shape of the cursor: lower half: ↔ (left-right arrows) upper half: ↑ (up-arrow) so it seems they fixed the discoverability :)

I just tried it. If you click in the top half the value immediately changes, no dragging required. It is really annoying.

I find that really useful

I agree that this feature is actually really nice. But I also agree with the other criticisms that its hard to discover.

> sometimes when I start it it doesn't display toolbox

Agreed. It's hard to imagine a scenario when you open a file in GIMP and don't want the tools. While there may be some such scenarios, it's hard to believe that it's a common case.

> when I open the toolbox it is (sometimes) a vertical line of buttons (single column) instead of 5 columns that I begged it countless times to be

Oh, yeah. Having the toolbox form factor changing and the tool buttons moving around (seemingly at random) is by far the most annoying part of GIMP for me. I don't actually much care what layout is chosen; I just want it to stay the same.

The formatting you chose forced me to have to drag a scrollbar to the right to read your comment...

please no :(

This. If anything GIMP is missing features for me. Especially the non-destructive editing and disk paging support you mentioned feel sorely lacking.

Floating point pixel values should be supported as of GIMP 2.10, though.

> Floating point pixel values should be supported as of GIMP 2.10, though.

True! I have just updated to 2.10 and it can open floating-point tiffs of one or three channels. The support is very limited, though. It seems to ignore negative values or values higher than 1, so it is mostly useless to me. Yet, I'm very happy to see new advances!

You might be interested in ImageJ [0] or FIJI [1] (which is ImageJ bundled with a bunch of plugins).

It can:

1.) handle hyperspectral images

2.) handle images with 32-bit floating-point pixels

3.) handle gigantic images, streaming from disk as necessary

4.) record edits as a macro, which can be replayed on other images

Unfortunately, I'm not aware of, and a little searching didn't uncover, any capability for handling complex pixel values. This could be (poorly) implemented with 2-channel images and some user macros for specially manipulating them.

[0] https://imagej.net/Welcome

[1] http://fiji.sc/

Thanks! There's plenty of software that supports these features (and does not require you to touch any--gasp--java). I am just sad that these basic things are not readily available in GIMP, which could otherwise attempt to be a sort of generic tool for image processing. They seem to be focused too much in color photography, while the tool is not directly useful to people working with images that are not of this kind (e.g., astronomical images, microscopy, satellite, radar, and mathematical image processing).

Off-topic:

Googling "complex-valued pixels" didn't bring up anything, but I'm interested in finding out more about that. What pixel-related information do the real/imaginary parts represent? What sort of applications does that have?

Radar images (e.g., those publicly available from the Sentinel 1 satellite) typically come as complex-valued images. You look at the norm of the complex numbers to understand the structures, but for interferometry you need the phase also.

If you compute the Fourier transform of a scalar-valued image, you obtain a complex-valued image. It would be nice to be able to process these transforms with gimp (e.g., to "paint" a few parts in black to set those frequencies to zero, thereby defining a band-pass filter).

Very cool, thanks!

GIMP is a bit of a learning process from Photoshop, but once you know where everything is in translation, it's really not too bad. I moved entirely to Linux and while I have feature requests for GIMP, it hasn't held any of my art back.

Their window/toolbox system sucks though. I have a hard time placing all windows where they need to be and even opening some of them. It's probably my biggest complaint right now.

GIMP's IWarp workflow is horrendous. And this is saying something - photoshop's liquify could be much better too.

> GIMP's IWarp workflow is horrendous.

Welcome to 2018 where GIMP 2.10 is available and features the Warp Transform tool that does the same (actually, more) and works directly on the canvas.

I haven't opened GIMP in a long while. Thanks for pointing this out!

I think the features you want are in a niche very far from general-purpose photo-editing. Moving GIMP in that direction would be the kind of mission-diluting step that can kill a project. What you're looking for a tool specialized for scientific use -- maybe try ImageJ?

My point exactly!

GIMP is GNU's image manipulation program, not photo manipulation program. Most images are not photos.

GIMP is called the GNU Image Manipulation Program, but that doesn't mean it should do every imaginable kind of image manipulation. Scientific image processing and the things that GIMP and Photoshop are useful for are different enough that to add all of ImageJ features to GIMP or vice versa would make them more confusing, waste developer time and focus, and overall hurt users. And I say this as a user of both.

Just use ImageJ!

I'm interested in the democratization of access to taxpayer-funded public high resolution images. So far, GIMP cannot easily open any of those, and it bothers me, because it is a useful tool otherwise. I do not want to install "scientific" software just for viewing and cropping a satellite image.

GIMP's UI is one of the worst I can think of.

Everything is counterintutive, starting from shortcuts, to menus, etc. etc., and since it's GTK2 it looks minuscule on hidpi screens.