i will try a higher cropping power, thanks
the way i read manga, it doesnt matter if the top bottom is in fullscreen, only left right. because i use more than one page in ereader to read one manga page.
the images are not stretched, they are upscalled.
I attached some images to give some examples and kcc configuration that i am using.
example 1 (the images with pirate flag): no watermark. left right is in fullscreen. this is what i am aiming for.
example 2: with watermark (on bottom right). there is a bigger margin on the right. so each square in the image is not as large as it could be.
In both cases, i have to "scroll"(turn the page) to read the whole manga page (one image).
EDIT: it seems that cropping power set at 3 reduces the margin on the right
but there are some pages that it didnt crop the number page. it seems, when set at 3, it work on side margins but it does not work well on page numbers (worse than set at 1)