imageperlimage-processingimagemagickperlmagick

Scaling of image to fixed width but not preserve the aspect ratio

I want to scale an image that way that the resulting image got a fixed width, but the heigth of the image stays the same. How can this be done?

Solution

  • You can do this at the command line:

    convert input.jpg -resize 3x\! output.jpg

    The ! forces the resize, and leaving the height blank leaves it unaffected.

    # Create it 50x50 and check
convert -size 50x50 xc:black  a.jpg
identify a.jpg
a.jpg JPEG 50x50 50x50+0+0 8-bit Gray 256c 173B 0.000u 0:00.009

# Resize and check
convert a.jpg -resize 3x\! out.jpg
identify out.jpg
out.jpg JPEG 3x50 3x50+0+0 8-bit Gray 256c 162B 0.000u 0:00.000

    And a Perl version of a similar thing:

    #!/usr/bin/perl
use strict;
use warnings;
use Image::Magick;
my $image;

$image=Image::Magick->new(size=>'500x500');
$image->Read('xc:white');
$image->write("out1.jpg");
$image->Resize(geometry => "3x!");
$image->write("out2.jpg");