[feature request] drop images, variable/rectangular crop toggle

[harusosake]

thank you for the program!

i am still missing a few small things that make your program a swiss army knife for me.

i would like to be more flexible with larger datasets (it's not uncommon to have some images you don't want in the dataset while editing them)
- drop images with del key?

also it would be great if i could switch between square crop and variable/rectangular crop (now that bucketing is more present you would think that cropping is not necessary, but still you would want to do some postprocessing and crop away some unwanted areas)
- toggle between square & variable/rectangular crop

[arenasys]

proper dataset management is on the todo list. deleting an image outright isn't an option since it would cause irreversible data loss by design. my idea is a Dataset tab next to the Output one, which will show the dataset as a grid of images. you could then hide or duplicate images in the dataset, hidden images wont show up in the rest of the GUI and wont be packaged, but you can still see them (grayed out probably) in the dataset tab and undo hiding them.

rectangular cropping would be quite complicated and im not sure how useful it would be. if you are training with bucketing i would suggest packaging with the scale mode to avoid cropping entirely.