comment on

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');
[download]

In reply to ImageMagick Point Query by bensonmonk

Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
Want more info? How to link or How to display code and escape characters are good places to start.


Do you know where your variables are?
	PerlMonks