ImageMagick Gradle Plugin

ImageMagick Gradle Plugin is a plugin to call ImageMagick CLI.

Prerequisites

ImageMagick should be installed and magick command should be available:

magick logo: logo.gif
magick identify logo.gif
magick logo.gif win:

Configuration

Apply an appropriate version of a plugin:

plugins {
    id 'ru.d-shap.imagemagick' version '1.1'
}

Configure the plugin with an imagemagick block. Configuration consist of a set of pipelines. Each pipeline is a set of commands applied to a set of source files. For example, one set of images should be converted from JPG to PNG format. Another set of images should be resized.

imagemagick {
    convert {
        ...
    }
    resize {
        ...
    }
}

For each pipeline the following should be specified:

• a set of source files
• a destination folder
• a set of commands, applied to the source files

For example, to resize an image, next magick command is used:

magick rose.jpg -resize 50% rose.png

The configuration will be the following:

imagemagick {
    resize {
        src 'source', { include 'rose.jpg' }
        dst 'gen'
        parameters {
            sourceFile()
            resize('50%')
            destinationFile('rose.png')
        }
    }
}

Source files

A command to pass a source file to magick command:

• sourceFile()

Destination files

Commands to pass a destination file to magick command:

• destinationFile()
• destinationFile('name.ext')
• destinationFile({ name, ext -> "${name}.${ext}" })

Parameters

Parameter name matches the function name in parameters block:

• crop(geometry)
• monochrome()
• rotate(degrees)

In this case parameters are passed with leading - character and the next command will be executed:

magick -crop geometry -monochrome -rotate degrees

Some parameters don't have a leading - character, for example canvas:none. In this case a closure should be passed to the function:

canvas({
    prefix = ''
    args = [':none']
})

Some parameters have - character in their name, for example -contrast-stretch geometry. Character - is not allowed in function names, so function contrast-stretch() can't be defined. So a - character should be replaced with _ character:

contrast_stretch(geometry)

Examples

Create a logo image

Configuration

imagemagick {
    pipeline {
        dst 'gen'
        parameters {
            logo({
                prefix = ''
                args = [':']
            })
            destinationFile('logo.gif')
        }
    }
}

Executed command

magick logo: <<PROJECT_ROOT>>\build\gen\logo.gif

Draw an image with multiple image processing operations

Configuration

imagemagick {
    pipeline {
        dst 'gen'
        parameters {
            size('320x85')
            canvas({
                prefix = ''
                args = [':none']
            })
            font('Bookman-DemiItalic')
            pointsize(72)
            draw('text 25,60 \'Magick\'')
            channel('RGBA')
            blur('0x6')
            fill('darkred')
            stroke('magenta')
            draw('text 25,60 \'Magick\'')
            destinationFile('magick.png')
        }
    }
}

Executed command

magick -size 320x85 canvas:none -font Bookman-DemiItalic -pointsize 72 -draw "text 25,60 'Magick" -channel RGBA -blur 0x6 -fill darkred -stroke magenta -draw "text 25,60 'Magick" <<PROJECT_ROOT>>\build\gen\magick.png

Convert images to JPG and change size

Configuration

imagemagick {
    jpgconvert {
        src 'src/main/resources/assets', { include '**/*.png' }
        dst 'gen'
        parameters {
            sourceFile()
            resize('20%')
            destinationFile({ name, ext -> "${name}.jpg" })
        }
    }
}

Executed command

magick <<PROJECT_ROOT>>\src\main\resources\assets\texture\texture.png -resize 20% <<PROJECT_ROOT>>\build\gen\texture\texture.jpg

Resize an image with improved quality

Configuration

imagemagick {
    resize {
        src 'src/main/resources/assets', { include '**/*.png' }
        dst 'gen'
        parameters {
            sourceFile()
            colorspace('RGB')
            sigmoidal_contrast({
                prefix = '+'
                args = [11.6933]
            })
            define('filter:filter=Sinc')
            define('filter:window=Jinc')
            define('filter:lobes=3')
            resize('400%')
            sigmoidal_contrast({
                prefix = '-'
                args = [11.6933]
            })
            colorspace('sRGB')
            destinationFile()
        }
    }
}

Executed command

magick <<PROJECT_ROOT>>\src\main\resources\assets\texture\texture.png -colorspace RGB +sigmoidal-contrast 11.6933 -define filter:filter=Sinc -define filter:window=Jinc -define filter:lobes=3 -resize 400% -sigmoidal-contrast 11.6933 -colorspace sRGB <<PROJECT_ROOT>>\build\gen\texture\texture.png