Imagick::setImageCompressionQuality

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Imagick::setImageCompressionQuality — Sets the image compression quality

Description

bool Imagick::setImageCompressionQuality ( int $quality )

Sets the image compression quality.

Parameters

quality: The image compression quality as an integer

Return Values

Returns TRUE on success.

Errors/Exceptions

Throws ImagickException on error.

Examples

Example #1 Imagick::setImageCompressionQuality()


<?php
function setImageCompressionQuality($imagePath, $quality) {
    $imagick = new \Imagick(realpath($imagePath));
    $imagick->setImageCompressionQuality($quality);
    header("Content-Type: image/jpg");
    echo $imagick->getImageBlob();
}

?>

User Contributed Notes

dylan dot arnold at gmail dot com

3 years ago


I had strange results when trying to get good png compression.

I used Imagick::COMPRESSION_ZIP

Here are a few file sizes for a few compression levels.

0: 236,100
1: 274,035
9: 258,379
50: 241,282
100: 240,156

Note the best result at 0. Also I got thrown off for a long time trying to get similar results to gimp. Make sure your image depth is set to 8, it appears to be 16 bits per channel, at least for me.

You can check with identify -verbose filename.png

You can also strip a bit more file size with $image->stripImage();

snipes2083 [at] yahoo com

6 years ago


This example shows how to set the compression type, set the compression quality, create a thumbnail and remove unnecessary data in order to reduce file size.



This will use the following functions in reference:

Imagick::setImageCompression

Imagick::setImageCompressionQuality

Imagick::stripImage

Imagick::thumbnailImage

Imagick::writeImage



<?php

    $image = 'image.jpg';

    $directory = '/path/to/image';

    $image_location = $directory . "/" . $image;

    $thumb_destination = $directory . "/t" . $image;

    $compression_type = Imagick::COMPRESSION_JPEG;

   

    $im = new Imagick($image_location);

    $thumbnail = $im->clone;



    $thumbnail->setImageCompression($compression_type);

    $thumbnail->setImageCompressionQuality(40);

    $thumbnail->stripImage();

    $thumbnail->thumbnailImage(100,null);

    $thumbnail->writeImage($thumb_destination);

?>



Now, obviously you don't have to do so much with the variables and the file location.  I only used so many to demonstrate where the images are coming from and where they are going.



NOTE:  The $thumbnail->thumbnailImage(100,null); keeps the aspect ration by setting the second parameter to null.  Read about this at Imagick::thumbnailImage



There is another way to create thumbnails that works quite well if you want to crop the image rather than using the entire image.  Check out Imagick::cropThumbnailImage

Anonymous

3 years ago


The default value fot the JPEG compression quality appears to be 86.