oh, in that case it's enough to go in the crop section, select "pic" to keep the current "picture" aspect ratio and resize the crop box
Your suggestion above doesn't work. Try it. It keeps the picture aspect ratio, but it crops the picture. I don't want to crop it, I want to shrink the number of pixels but keep the same image (with loss of clarity because reducing pixels).
It allows you to resize either in terms of pixel count or percentage. The percentage approach is very nice for just putting 50 in both horizontal and vertical fields and getting an image half as large in both dimensions, but showing the same image (with reduced quality, because fewer pixels) and at the same aspect ratio.
I preferred just having an input with the correct pixels rather than % (to keep UI clean) but you'll get the same result