Retrieve the coordinates corresponding to a certain color

[badabou]

Hello,

Is it possible to retrieve the coordinates x,y (and width,height) of a shape in an image with imagemagick ?

Let me explain :

There is a function in flash which recovers an area corresponding to a certain color (getColorBoundsRect) :



With this picture, the function will return the coordinates of the area filled with the red circle.

I would do the same with imagemagick but I do not know if this is possible.

Thank you

[fmw42]

Use -trim without a following +repage, then get the geometry size and offset


convert 92246458.png +repage -fuzz 10% -trim 92246458_trim.png
size=`convert 92246458_trim.png -format "%P" info:`
offsets=`convert 92246458_trim.png -format "%O" info:`
echo "size=$size"
echo "offsets=$offsets"

choose an appropriate fuzz value to separate the background from the circle (presumably without the white square).

see
http://www.imagemagick.org/script/escape.php
http://www.imagemagick.org/Usage/crop/#trim

The above is for unix variables. For windows, see http://www.imagemagick.org/Usage/windows/

[anthony]

Or are you trying to get the locations of all red pixels? Just the bounding box indicated in white? Or just the 'best guess' at the center and diameter of a circle? Perhaps you just one a single coordinate anywhere within the circle? Or maybe the mask of the circle?

There are lots of possibilities as to your meaning of 'coordinates of the shape'.