Hello !
I did not found how to use the resizetobox / croptobox options to have the thumbnails like in lightroom Library module.
Precisely, when the "matrix" of thumbnails is displayed, each little image has to be reduced proportionally to fit into a square of given dimension. No crop, but only a resize of the image.
Of course, there would be a margin between the image and the border of the square, on the top and the bottom for horizontal images, and on the right and left sides of vertical images...
Do you understand what I mean ?
There is a screenshot right here :
Thank you very very much for your help !
MacDo