HJG I have some images on a canvas, and I want to get the color of the pixel under the cursor.
Right now, this works only for an image placed on the canvas a 0,0 :
package require Img
proc int x { expr int($x) }
proc ShowPixel {x y i} {
set c "- - -"
catch { set c [$::img1 get $x $y] }
wm title . "$x $y #$i : $c"
}
set fn gosmall.gif
set img1 [image create photo -file $fn]
pack [canvas .c]
.c create image 0 0 -image $img1 -anchor nw -tag Copy1
.c create image 80 80 -image $img1 -anchor nw -tag Copy2
bind .c <Motion> { ShowPixel [int [%W canvasx %x]] [int [%W canvasy %y]] [%W find withtag current] }The RGB-values of the pixel under the cursor are shown only for the first copy of the image...
I can query the coordinates of an item/image on the canvas with bbox (to adjust coordinates within the image vs. the screen-coordinates given by the cursor), but how do I pass the item (as opposed to its id) to the proc ShowPixel ?