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how can draw a null image?

Posted: 2008-05-25T05:44:24-07:00
by haibara
i want a null image, it means rgba be all zero(?)

convert -size heightxwidth -background none {result}?

it seems wrong and infos me lacking of source

what should i do?

regards

Re: how can draw a null image?

Posted: 2008-05-25T10:08:25-07:00
by fmw42
try

convert -size 100x100 xc:none out.png

or

convert -size 100x100 xc:"rgba(0,0,0,0)" out.png


see http://www.imagemagick.org/Usage/canvas/#solid in the section on transparent canvas

Re: how can draw a null image?

Posted: 2008-06-04T22:56:19-07:00
by anthony
Do not confuse what you are calling a null image which was IM generated using null:
That image is special in that it is a single transparent pixel that is used to represent things like, errors, gaps in montage, to two separate image sequences in -layers composite (such as composing animations together).

That image can be saved, but reading a saved null: image will NOT be regarded as the special null: image that IM uses for special purposes (I consider this a bug, but an acceptable one).