NAME

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

VERSION

This document describes version 0.023 of calc-image-resized-size (from Perl distribution App-ImageMagickUtils), released on 2024-08-29.

SYNOPSIS

calc-image-resized-size --help (or -h, -?)

calc-image-resized-size --version (or -v)

calc-image-resized-size [--format=name|--json] [--(no)naked-res] [--page-result[=program]|--view-result[=program]] -- <size> <resize>

See examples in the "EXAMPLES" section.

OPTIONS

* marks required options.

Main options

--resize=s*

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

Can also be specified as the 2nd command-line argument.

--size=s*

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

Can also be specified as the 1st command-line argument.

Output options

--format=s

Choose output format, e.g. json, text.

Default value:

undef

Output can be displayed in multiple formats, and a suitable default format is chosen depending on the application and/or whether output destination is interactive terminal (i.e. whether output is piped). This option specifically chooses an output format.

--json

Set output format to json.

--naked-res

When outputing as JSON, strip result envelope.

Default value:

By default, when outputing as JSON, the full enveloped result is returned, e.g.:

[200,"OK",[1,2,3],{"func.extra"=>4}]

The reason is so you can get the status (1st element), status message (2nd element) as well as result metadata/extra result (4th element) instead of just the result (3rd element). However, sometimes you want just the result, e.g. when you want to pipe the result for more post-processing. In this case you can use --naked-res so you just get:

[1,2,3]

--page-result

Filter output through a pager.

This option will pipe the output to a specified pager program. If pager program is not specified, a suitable default e.g. less is chosen.

--view-result

View output using a viewer.

This option will first save the output to a temporary file, then open a viewer program to view the temporary file. If a viewer program is not chosen, a suitable default, e.g. the browser, is chosen.

Other options

--help, -h, -?: Display help message and exit.
--version, -v: Display program's version and exit.

COMPLETION

This script has shell tab completion capability with support for several shells.

bash

To activate bash completion for this script, put:

complete -C calc-image-resized-size calc-image-resized-size

in your bash startup (e.g. ~/.bashrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.

It is recommended, however, that you install modules using cpanm-shcompgen which can activate shell completion for scripts immediately.

tcsh

To activate tcsh completion for this script, put:

complete calc-image-resized-size 'p/*/`calc-image-resized-size`/'

in your tcsh startup (e.g. ~/.tcshrc). Your next shell session will then recognize tab completion for the command. Or, you can also directly execute the line above in your shell to activate immediately.

It is also recommended to install shcompgen (see above).

other shells

For fish and zsh, install shcompgen as described above.

EXAMPLES

no resizing

% calc-image-resized-size 2592x1944 ''
2592x1944

scale (down) to 20%

% calc-image-resized-size 2592x1944 20%
518x388

scale (down) width to 20% but height to 40%

% calc-image-resized-size 2592x1944 20%x40%
518x777

scale (down) width to 20% but height to 40% (first percent sign is optional)

% calc-image-resized-size 2592x1944 20x40%
518x777

set width to 1024px

% calc-image-resized-size 2592x1944 1024
1024x768

shrink width to 1024px

% calc-image-resized-size 2592x1944 '1024>'
1024x768

shrink width to 10240px (no effect since width is already less than 10240px)

% calc-image-resized-size 2592x1944 '10240>'
2592x1944

enlarge width to 1024px (no effect since width is already greater than 1024px

% calc-image-resized-size 2592x1944 1024^
2592x1944

enlarge width to 10240px

% calc-image-resized-size 2592x1944 10240^
10240x7680

set height to 1024px

% calc-image-resized-size 2592x1944 x1024
1365x1024

shrink height to 768px

% calc-image-resized-size 2592x1944 'x768>'
1024x768

shrink height to 7680px (no effect since height is already less than 7680px)

% calc-image-resized-size 2592x1944 'x7680>'
2592x1944

enlarge height to 768px (no effect since height is already greater than 768px)

% calc-image-resized-size 2592x1944 x768^
2592x1944

enlarge height to 7680px

% calc-image-resized-size 2592x1944 x7680^
10240x7680

fit image inside 20000x10000 (no effect since it already fits)

% calc-image-resized-size 2592x1944 20000x10000
2592x1944

fit image inside 20000x1000 (height is reduced to 1000 to make the image fit)

% calc-image-resized-size 2592x1944 20000x1000
1333x1000

fit image inside 100x200

% calc-image-resized-size 2592x1944 100x200
100x75

fit image inside 100x100

% calc-image-resized-size 2592x1944 100x100
100x75

fit a 10000x5000 area inside image

% calc-image-resized-size 2592x1944 10000x5000^
10000x7500

fit a 5000x10000 area inside image

% calc-image-resized-size 2592x1944 5000x10000^
13333x10000

fit a 100x100 area inside image (no effect since the image can already fit that area)

% calc-image-resized-size 2592x1944 100x100^
2592x1944

set dimension to 100x100

% calc-image-resized-size 2592x1944 100x100!
100x100

shrink image to fit inside 10000x5000px (no effect since image already fits)

% calc-image-resized-size 2592x1944 '10000x5000>'
2592x1944

shrink image to fit inside 2000x1000px

% calc-image-resized-size 2592x1944 '2000x1000>'
1333x1000

shrink image to fit inside 100x100px

% calc-image-resized-size 2592x1944 '100x100>'
100x75

enlarge image to fit 10000x5000px inside it

% calc-image-resized-size 2592x1944 '10000x5000<'
10000x7500

enlarge image to fit 5000x10000px inside it

% calc-image-resized-size 2592x1944 '5000x10000<'
13333x10000

enlarge image to fit 3000x1000px inside it (no effect since image already fits)

% calc-image-resized-size 2592x1944 '3000x1000<'
2592x1944

shrink shortest side to 1024px

% calc-image-resized-size 2592x1944 '1024^>'
1365x1024

shrink shortest side to 10240px (no effect since shortest side 1944px is already less than 10240px)

% calc-image-resized-size 2592x1944 '10240^>'
2592x1944

enlarge shortest side to 1024px (no effect since shortest side is already greater than 1024px)

% calc-image-resized-size 2592x1944 '1024^<'
2592x1944

enlarge shortest side to 10240px

% calc-image-resized-size 2592x1944 '10240^<'
13653x10240

shrink longest side to 1024px

% calc-image-resized-size 2592x1944 '^1024>'
1024x768

shrink longest side to 10240px (no effect since longest side 2592px is already less than 10240px)

% calc-image-resized-size 2592x1944 '^10240>'
2592x1944

enlarge longest side to 1024px (no effect since longest side 2592px is already greater than 1024px)

% calc-image-resized-size 2592x1944 '^1024<'
2592x1944

enlarge longest side to 10240px

% calc-image-resized-size 2592x1944 '^10240<'
10240x7680

HOMEPAGE

Please visit the project's homepage at https://metacpan.org/release/App-ImageMagickUtils.

SOURCE

Source repository is at https://github.com/perlancar/perl-App-ImageMagickUtils.

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 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=App-ImageMagickUtils

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.

To install App::ImageMagickUtils, copy and paste the appropriate command in to your terminal.

cpanm

cpanm App::ImageMagickUtils

CPAN shell

perl -MCPAN -e shell
install App::ImageMagickUtils

For more information on module installation, please visit the detailed CPAN module installation guide.

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