ulis, 2003-08-22: A little proc to adapt a gray image with transparency to a colored background.
Before:
After:
The proc edit
proc colorize {image color} {
# get image sizes
set width [image width $image]
set height [image height $image]
# get color's R G B
lassign [winfo rgb . $color] rr gg bb
# compute new colors
set colors {}
for {set y 0} {$y < $height} {incr y} {
set row {}
for {set x 0} {$x < $width} {incr x} {
# save transparency
lappend trans $x $y [$image transparency get $x $y]
# compute the new color
lassign [$image get $x $y] r g b
set r [expr {round($r * $rr / 256)}]
set g [expr {round($g * $gg / 256)}]
set b [expr {round($b * $bb / 256)}]
# append to the current row
lappend row [format #%4.4x%4.4x%4.4x $r $g $b]
}
# append the row
lappend colors $row
}
# set new image
img put $colors
# restore transparency
foreach {x y t} $trans {
$image transparency set $x $y $t
}
}
The demo edit
# =========
# demo
# =========
wm title . colorize
# get a gray image
image create photo img -file gray-image.gif
# add colors
colorize img azure
# display
set width [image width img]
set height [image height img]
canvas .c -width [incr width 4] -height [incr height 4] -bg beige
.c create image 2 2 -anchor nw -image img
pack .c
