Imagick
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Imagick::setImageCompressionQuality

(No version information available, might only be in SVN)

Imagick::setImageCompressionQuality — Sets the image compression quality

说明

bool Imagick::setImageCompressionQuality ( int $quality )

Sets the image compression quality.

参数

quality

The image compression quality as an integer

返回值

成功时返回 TRUE .

错误/异常

错误时抛出 ImagickException .

Imagick
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PHP手册 - N: Sets the image compression quality

用户评论:

snipes2083 [at] yahoo com (28-Mar-2010 07:35)

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