ImageMagick Point Query

[bensonmonk]

I want to use ImageMagick to edit an existing image by making some selected points a specific colour.
I am trying to use the Draw command with the ‘point’ primitive. However, I can only get a black point regardless of what colour I am trying to set.
This is shown in the Perl code below where:
1. I draw a blue rectangle;
2. Try and set a number of points to white in a rectangle that partly overlaps the blue rectangle.
However, I get black points in the rectangle.
How can I set white (and any other colour) points?

use Image::Magick;
my ($col, $img_width, $row, $img_height);
# Create a new image
my $im = Image::Magick->new(size => '400x300');
# Give it a white background
$im->Read('xc:white');
# Put a rectangle in there somewhere
$im->Draw(primitive => 'rectangle',
          points    => '0,129 199,169',
          fill      => 'blue',
          stroke    => 'blue');
for($col = 50; $col < 100; $col ++ ) {
    for ($row = 150; $row < 200; $row ++ ) {
        $im->Draw(primitive    => 'point',
        points    => "$col,$row",
        stroke    => 'white');
    }
}
$im->Write('pointquery.png');

[zentara]

How can I set white (and any other colour) points?

Set the -fill option on the point primitives.

#!/usr/bin/perl
use Image::Magick;

my ($col, $img_width, $row, $img_height);
# Create a new image

my $im = Image::Magick->new(size => '400x300');

# Give it a white background

$im->Read('xc:white');


# Put a rectangle in there somewhere
$im->Draw(primitive => 'rectangle',
          points    => '0,129 199,169',
          fill      => 'blue',
          stroke    => 'blue');


for($col = 50; $col < 100; $col ++ ) {
    for ($row = 150; $row < 200; $row ++ ) {
        $im->Draw(
         primitive => 'point',
         points    => "$col,$row",
         stroke    => 'white',
         fill => 'white'   # you missed this fill right here!!!!!!!!!!
+!
         );
    
    }
}

$im->Write("$0.png");

[bensonmonk]

Exactly!! Many thanks.

[ColonelPanic]

Just a quick usage note: in Perl there is almost always an easier solution than C-style for loops

for my $col (50..99) 
{
    for my $row (150..199) 
    {
        #same code here
    }
}

It's a small point, but in my experience incorrectly handled iterator variables are a common source of mistakes. Letting Perl take care of that means fewer headaches.