NAME

Math::Image::CalcResized - Calculate dimensions of image/video resized by ImageMagick-like geometry specification

VERSION

This document describes version 0.006 of Math::Image::CalcResized (from Perl distribution Math-Image-CalcResized), released on 2024-08-29.

FUNCTIONS

calc_image_resized_size

Usage:

calc_image_resized_size(%args) -> [$status_code, $reason, $payload, \%result_meta]

Given size of an image (in WxH, e.g. "2592x1944") and ImageMagick-like resize instruction (e.g. "1024p>"), calculate new resized image.

Examples:

  • no resizing:

    calc_image_resized_size(size => "2592x1944", resize => ""); # -> [200, "OK (envelope generated)", "2592x1944"]
  • scale (down) to 20%:

    calc_image_resized_size(size => "2592x1944", resize => "20%"); # -> [200, "OK (envelope generated)", "518x388"]
  • scale (down) width to 20% but height to 40%:

    calc_image_resized_size(size => "2592x1944", resize => "20%x40%");

    Result:

    [200, "OK (envelope generated)", "518x777"]
  • scale (down) width to 20% but height to 40% (first percent sign is optional):

    calc_image_resized_size(size => "2592x1944", resize => "20x40%");

    Result:

    [200, "OK (envelope generated)", "518x777"]
  • set width to 1024px:

    calc_image_resized_size(size => "2592x1944", resize => 1024); # -> [200, "OK (envelope generated)", "1024x768"]
  • shrink width to 1024px:

    calc_image_resized_size(size => "2592x1944", resize => "1024>");

    Result:

    [200, "OK (envelope generated)", "1024x768"]
  • shrink width to 10240px (no effect since width is already less than 10240px):

    calc_image_resized_size(size => "2592x1944", resize => "10240>");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge width to 1024px (no effect since width is already greater than 1024px:

    calc_image_resized_size(size => "2592x1944", resize => "1024^");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge width to 10240px:

    calc_image_resized_size(size => "2592x1944", resize => "10240^");

    Result:

    [200, "OK (envelope generated)", "10240x7680"]
  • set height to 1024px:

    calc_image_resized_size(size => "2592x1944", resize => "x1024");

    Result:

    [200, "OK (envelope generated)", "1365x1024"]
  • shrink height to 768px:

    calc_image_resized_size(size => "2592x1944", resize => "x768>");

    Result:

    [200, "OK (envelope generated)", "1024x768"]
  • shrink height to 7680px (no effect since height is already less than 7680px):

    calc_image_resized_size(size => "2592x1944", resize => "x7680>");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge height to 768px (no effect since height is already greater than 768px):

    calc_image_resized_size(size => "2592x1944", resize => "x768^");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge height to 7680px:

    calc_image_resized_size(size => "2592x1944", resize => "x7680^");

    Result:

    [200, "OK (envelope generated)", "10240x7680"]
  • fit image inside 20000x10000 (no effect since it already fits):

    calc_image_resized_size(size => "2592x1944", resize => "20000x10000");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • fit image inside 20000x1000 (height is reduced to 1000 to make the image fit):

    calc_image_resized_size(size => "2592x1944", resize => "20000x1000");

    Result:

    [200, "OK (envelope generated)", "1333x1000"]
  • fit image inside 100x200:

    calc_image_resized_size(size => "2592x1944", resize => "100x200");

    Result:

    [200, "OK (envelope generated)", "100x75"]
  • fit image inside 100x100:

    calc_image_resized_size(size => "2592x1944", resize => "100x100");

    Result:

    [200, "OK (envelope generated)", "100x75"]
  • fit a 10000x5000 area inside image:

    calc_image_resized_size(size => "2592x1944", resize => "10000x5000^");

    Result:

    [200, "OK (envelope generated)", "10000x7500"]
  • fit a 5000x10000 area inside image:

    calc_image_resized_size(size => "2592x1944", resize => "5000x10000^");

    Result:

    [200, "OK (envelope generated)", "13333x10000"]
  • fit a 100x100 area inside image (no effect since the image can already fit that area):

    calc_image_resized_size(size => "2592x1944", resize => "100x100^");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • set dimension to 100x100:

    calc_image_resized_size(size => "2592x1944", resize => "100x100!");

    Result:

    [200, "OK (envelope generated)", "100x100"]
  • shrink image to fit inside 10000x5000px (no effect since image already fits):

    calc_image_resized_size(size => "2592x1944", resize => "10000x5000>");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • shrink image to fit inside 2000x1000px:

    calc_image_resized_size(size => "2592x1944", resize => "2000x1000>");

    Result:

    [200, "OK (envelope generated)", "1333x1000"]
  • shrink image to fit inside 100x100px:

    calc_image_resized_size(size => "2592x1944", resize => "100x100>");

    Result:

    [200, "OK (envelope generated)", "100x75"]
  • enlarge image to fit 10000x5000px inside it:

    calc_image_resized_size(size => "2592x1944", resize => "10000x5000<");

    Result:

    [200, "OK (envelope generated)", "10000x7500"]
  • enlarge image to fit 5000x10000px inside it:

    calc_image_resized_size(size => "2592x1944", resize => "5000x10000<");

    Result:

    [200, "OK (envelope generated)", "13333x10000"]
  • enlarge image to fit 3000x1000px inside it (no effect since image already fits):

    calc_image_resized_size(size => "2592x1944", resize => "3000x1000<");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • shrink shortest side to 1024px:

    calc_image_resized_size(size => "2592x1944", resize => "1024^>");

    Result:

    [200, "OK (envelope generated)", "1365x1024"]
  • shrink shortest side to 10240px (no effect since shortest side 1944px is already less than 10240px):

    calc_image_resized_size(size => "2592x1944", resize => "10240^>");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge shortest side to 1024px (no effect since shortest side is already greater than 1024px):

    calc_image_resized_size(size => "2592x1944", resize => "1024^<");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge shortest side to 10240px:

    calc_image_resized_size(size => "2592x1944", resize => "10240^<");

    Result:

    [200, "OK (envelope generated)", "13653x10240"]
  • shrink longest side to 1024px:

    calc_image_resized_size(size => "2592x1944", resize => "^1024>");

    Result:

    [200, "OK (envelope generated)", "1024x768"]
  • shrink longest side to 10240px (no effect since longest side 2592px is already less than 10240px):

    calc_image_resized_size(size => "2592x1944", resize => "^10240>");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge longest side to 1024px (no effect since longest side 2592px is already greater than 1024px):

    calc_image_resized_size(size => "2592x1944", resize => "^1024<");

    Result:

    [200, "OK (envelope generated)", "2592x1944"]
  • enlarge longest side to 10240px:

    calc_image_resized_size(size => "2592x1944", resize => "^10240<");

    Result:

    [200, "OK (envelope generated)", "10240x7680"]

This function is not exported by default, but exportable.

Arguments ('*' denotes required arguments):

  • resize* => str

    Resize instruction, follows ImageMagick format.

    Resize instruction can be given in several formats:

    Syntax                     Meaning
    -------------------------- ----------------------------------------------------------------
    ""                         No resizing.
    
    SCALE"%"                   Height and width both scaled by specified percentage.
    SCALEX"%x"SCALEY"%"        Height and width individually scaled by specified percentages. (Only one % symbol needed.)
    
    WIDTH                      Width given, height automagically selected to preserve aspect ratio.
    WIDTH">"                   Shrink width if larger, height automagically selected to preserve aspect ratio.
    WIDTH"^"                   Enlarge width if smaller, height automagically selected to preserve aspect ratio.
    
    "x"HEIGHT                  Height given, width automagically selected to preserve aspect ratio.
    "x"HEIGHT">"               Shrink height if larger, width automagically selected to preserve aspect ratio.
    "x"HEIGHT"^"               Enlarge height if smaller, width automagically selected to preserve aspect ratio.
    
    WIDTH"x"HEIGHT             Maximum values of height and width given, aspect ratio preserved.
    WIDTH"x"HEIGHT"^"          Minimum values of height and width given, aspect ratio preserved.
    WIDTH"x"HEIGHT"!"          Width and height emphatically given, original aspect ratio ignored.
    WIDTH"x"HEIGHT">"          Shrinks an image with dimension(s) larger than the corresponding width and/or height argument(s).
    WIDTH"x"HEIGHT"<"          Shrinks an image with dimension(s) larger than the corresponding width and/or height argument(s).
    
    NUMBER"^>"                 Shrink shortest side if larger than number, aspect ratio preserved.
    NUMBER"^<"                 Enlarge shortest side if larger than number, aspect ratio preserved.
    "^"NUMBER">"               Shrink longer side if larger than number, aspect ratio preserved.
    "^"NUMBER"<"               Enlarge longer side if larger than number, aspect ratio preserved.

    Currently unsupported:

    AREA"@"                    Resize image to have specified area in pixels. Aspect ratio is preserved.
    X":"Y                      Here x and y denotes an aspect ratio (e.g. 3:2 = 1.5).

    Ref: http://www.imagemagick.org/script/command-line-processing.php#geometry

  • size* => str

    Image/video size, in <width>x<height> format, e.g. 2592x1944.

Returns an enveloped result (an array).

First element ($status_code) is an integer containing HTTP-like status code (200 means OK, 4xx caller error, 5xx function error). Second element ($reason) is a string containing error message, or something like "OK" if status is 200. Third element ($payload) is the actual result, but usually not present when enveloped result is an error response ($status_code is not 2xx). Fourth element (%result_meta) is called result metadata and is optional, a hash that contains extra information, much like how HTTP response headers provide additional metadata.

Return value: (any)

image_resize_notation_to_human

Usage:

image_resize_notation_to_human(%args) -> [$status_code, $reason, $payload, \%result_meta]

Translate ImageMagick-like resize notation (e.g. "720^>") to human-friendly text (e.g. "shrink shortest side to 720px").

Examples:

  • Example #1:

    image_resize_notation_to_human(resize => ""); # -> [200, "OK (envelope generated)", "no resizing"]
  • Example #2:

    image_resize_notation_to_human(resize => "50%"); # -> [200, "OK (envelope generated)", "scale to 50%"]
  • Example #3:

    image_resize_notation_to_human(resize => "50%x50%");

    Result:

    [
      200,
      "OK (envelope generated)",
      "scale width to 50%, height to 50%",
    ]
  • Example #4:

    image_resize_notation_to_human(resize => 720); # -> [200, "OK (envelope generated)", "set width to 720px"]
  • Example #5:

    image_resize_notation_to_human(resize => "720>"); # -> [200, "OK (envelope generated)", "shrink width to 720px"]
  • Example #6:

    image_resize_notation_to_human(resize => "720^"); # -> [200, "OK (envelope generated)", "enlarge width to 720px"]
  • Example #7:

    image_resize_notation_to_human(resize => "x720"); # -> [200, "OK (envelope generated)", "set height to 720px"]
  • Example #8:

    image_resize_notation_to_human(resize => "x720>"); # -> [200, "OK (envelope generated)", "shrink height to 720px"]
  • Example #9:

    image_resize_notation_to_human(resize => "x720^"); # -> [200, "OK (envelope generated)", "enlarge height to 720px"]
  • Example #10:

    image_resize_notation_to_human(resize => "640x480"); # -> [200, "OK (envelope generated)", "fit image inside 640x480"]
  • Example #11:

    image_resize_notation_to_human(resize => "640x480^");

    Result:

    [
      200,
      "OK (envelope generated)",
      "fit image to fit 640x480 inside it",
    ]
  • Example #12:

    image_resize_notation_to_human(resize => "640x480>");

    Result:

    [
      200,
      "OK (envelope generated)",
      "shrink image to fit inside 640x480",
    ]
  • Example #13:

    image_resize_notation_to_human(resize => "640x480<");

    Result:

    [
      200,
      "OK (envelope generated)",
      "enlarge image to fit 640x480 inside it",
    ]
  • Example #14:

    image_resize_notation_to_human(resize => "640x480!");

    Result:

    [200, "OK (envelope generated)", "set dimension to 640x480"]
  • Example #15:

    image_resize_notation_to_human(resize => "720^>");

    Result:

    [
      200,
      "OK (envelope generated)",
      "shrink shortest side to 720px",
    ]
  • Example #16:

    image_resize_notation_to_human(resize => "720^<");

    Result:

    [
      200,
      "OK (envelope generated)",
      "enlarge shortest side to 720px",
    ]
  • Example #17:

    image_resize_notation_to_human(resize => "^720>");

    Result:

    [200, "OK (envelope generated)", "shrink longest side to 720px"]
  • Example #18:

    image_resize_notation_to_human(resize => "^720<");

    Result:

    [
      200,
      "OK (envelope generated)",
      "enlarge longest side to 720px",
    ]

Resize notation supports most syntax from ImageMagick geometry. See Math::Image::CalcResized and ImageMagick documentation on geometry for more details.

This function is not exported.

Arguments ('*' denotes required arguments):

  • resize* => str

    (No description)

Returns an enveloped result (an array).

First element ($status_code) is an integer containing HTTP-like status code (200 means OK, 4xx caller error, 5xx function error). Second element ($reason) is a string containing error message, or something like "OK" if status is 200. Third element ($payload) is the actual result, but usually not present when enveloped result is an error response ($status_code is not 2xx). Fourth element (%result_meta) is called result metadata and is optional, a hash that contains extra information, much like how HTTP response headers provide additional metadata.

Return value: (any)

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/Math-Image-CalcResized.

SOURCE

Source repository is at https://github.com/perlancar/perl-Math-Image-CalcResized.

SEE ALSO

AUTHOR

perlancar <perlancar@cpan.org>

CONTRIBUTING

To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then test via:

% prove -l

If you want to build the distribution (e.g. to try to install it locally on your system), you can install Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE

This software is copyright (c) 2024, 2021, 2020 by perlancar <perlancar@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

BUGS

Please report any bugs or feature requests on the bugtracker website https://rt.cpan.org/Public/Dist/Display.html?Name=Math-Image-CalcResized

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.