How to crop at NConvert without knowing image size?

[Werner T.]

I'm sure I'm really stupid. I simply want to cut the first 10 pixel at the top of many images without knowing the size of the images and without resizing them.
NConvert wants "crop x y w h". What would be the correct entries for w and h? Leave them empty messes other paramters, "0" doesn't do anything and "100%" is interpreted as 100 pixel.

[Werner T.]

I know found a solution by myself: Use a much too high value for w and h. BTW: Perhaps the documentation of NConvert should be a little bot more verboose.

[xnview]

I know found a solution by myself: Use a much too high value for w and h. BTW: Perhaps the documentation of NConvert should be a little bot more verboose.

Yes i know