I'm using im4java api to crop images. I never used command-line for imagemagic.
there are function, crop(int width,int height,int x, int y, String special)
crop(int width,int height,int x, int y, Character special)
I can understand, what are first 4 parameters(height, width, x ,y) for. Can anybody explain to me, what are that fifth parameters (String special and Character special) for?
and what are the possible values? Their documentation is clueless.
I think the authours probably expect users to be familiar with the command-line version of ImageMagick...
I don't know if this answer is correct, I am just assuming that it is related to the special operators available on the command line after the geometry/size settings. Some of these are:
< - shrinks images with dimensions less than those given, ignoring larger ones
> - shrinks images with dimensions larger than those given, ignoring smaller ones
! - which ignores aspect ratio and focres exact output size
@ - which specifies the total number of pixels (i.e. area) of the output image, regardless of whether the image is tall or wide. So, @1000 will produce an image with somewhere between 1000x1, 1x1000 or 33x33 but never with more than 1,000 pixels in toto.
% - allows you to resize by percentage, i.e. 50% which saves you having to get the dimensions and then do some maths.
There is a fuller list here.