Lossless JPEG crop GUI for Linux

Question

I need a tool to crop pictures:

• Allows me to select a zone (graphical user interface).
• Crops JPEG files without any loss of quality. This means that it only allows me to select a zone at particular points (iMCU boundary).
• When selecting the zone, show the real place at which it will crop (typically a few pixels off the place where my mouse is).
• Gratis, ideally open source.
• Works on Linux, callable via right-click on JPEG file from Nautilus
• Very fast to start, even when called for the first time since rebooting my computer.

Answer 1

CropGUI can do that.

Strong points:

• Extremely fast to start.
• Does the lossless crop.
• Open source (GPLv2).

Weak points:

• It is a bit bothersome to install (clone from GitHub and install the dependencies manually).
• The user interface is very rough. For instance, it does not tell you that it has saved the file nor where. So, you'll have to check the README and practice for 2 minutes before you can get fully productive.
• Two executables are included, cropgtk.py does not show you the final zone, but the older cropgui.py does.

Answer 2

CropGUI [...] Weak points: [...] It is a bit bothersome to install

I have been using CropGUI too for years.

I'm in the process of building an alternative: CropGuiNeu

It's mostly for educational purposes. I also did some work on the CropGUI install script. You can find my version, which is to be used only with CropGUI not CropGUNeu, here.

Right now you can install it on Linux with:

pipx install git+https://github.com/lwbt/CropGuiNeu.git

However, you will also need to install jpegtran.

I successfully built the app with flatpak-builder and I hope I can publish it soon on Flathub, so that there is finally an easy way for a simple tool.

Advantages:

• A bit easier to install and uninstall.
• Gnome header bar based design.

Disadvantages:

• Only basic crop functionality has been implemented yet.