How to know the image's transparent space?

[fmw42]

My error. Snibgo is correct -- it could be any color. Any perfectly constant color will trim to 0x0.

[niyanwen]

but if plus x,y offset equals image's full weight and height ? can we assume it is transparent?

[snibgo]

Try them:

Code: Select all

magick -size 10x10 xc:White -format %@ info:
magick: geometry does not contain image `' @ warning/attribute.c/GetImageBoundingBox/240.
0x0+10+10

magick -size 10x10 xc:None -format %@ info:
magick: geometry does not contain image `' @ warning/attribute.c/GetImageBoundingBox/240.
0x0+10+10

There is no difference betwen "none" (transparent black) and "white".

[fmw42]

The +X+Y = +10+10 is off the image just past the last pixel (at +9+9). It is not the width and height. It is an offset.