Imagick::cropThumbnailImage

(PECL imagick 2, PECL imagick 3)

Imagick::cropThumbnailImage — 切り取ってサムネイルを作成する

説明

public Imagick::cropThumbnailImage(int $width, int $height, bool $legacy = false): bool

固定サイズのサムネイルを作成します。まず画像のサイズを拡大あるいは縮小し、指定した範囲を中心から切り取ります。

パラメータ

width: サムネイルの幅。
height: サムネイルの高さ。

戻り値

成功した場合に true を返します。

エラー / 例外

エラー時に ImagickException をスローします。

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User Contributed Notes 3 notes

down

martijn at elicit dot nl ¶

14 years ago

In my opinion this function is not working as expected, tested for imagemagick version 6.3.7 

As described above, the function returns an image with a fixed height and a variable width. Here's a fix that will return a cropped thumbnail with the defined dimensions, without variations in the dimensions.

<?php
// define widescreen dimensions
$width = 160;
$height = 90;

// load an image
$i = new Imagick("your image file");
// get the current image dimensions
$geo = $i->getImageGeometry();

// crop the image
if(($geo['width']/$width) < ($geo['height']/$height))
{
    $i->cropImage($geo['width'], floor($height*$geo['width']/$width), 0, (($geo['height']-($height*$geo['width']/$width))/2));
}
else
{
    $i->cropImage(ceil($width*$geo['height']/$height), $geo['height'], (($geo['width']-($width*$geo['height']/$height))/2), 0);
}
// thumbnail the image
$i->ThumbnailImage($width,$height,true);

// save or show or whatever the image
$i->setImageFormat("png");
header("Content-Type: image/png");
exit($i);
?>

down

sonsandsons at gmail dot com ¶

12 years ago

It's worth noting that using cropThumbnailImage can appear to give undesired results if you're using .gif image formats. If you are using .gif's, you'll need to compliment this function with a removal of the canvas.

<?php

//instantiate the image magick class
$image = new Imagick($image_path);

//crop and resize the image
$image->cropThumbnailImage(100,100);

//remove the canvas
$image->setImagePage(0, 0, 0, 0);

?>

down

benford at bluhelix dot com ¶

15 years ago

I found a relevant posting complete with demo code at this site:
http://valokuva.org/?p=8

Sample code goes like this:
<?php
/* Read the image */
$im = new imagick( "test.png" );
/* create the thumbnail */
$im->cropThumbnailImage( 80, 80 );
/* Write to a file */
$im->writeImage( "th_80x80_test.png" );
?>

This is a specialization of the cropImage method. At a high level, this method will create a thumbnail of a given image, with the thumbnail sized at ($width, $height). 

If the thumbnail does not match the aspect ratio of the source image, this is the method to use. The thumbnail will capture the entire image on the shorter edge of the source image (ie, vertical size on a landscape image). Then the thumbnail will be scaled down to meet your target height, while preserving the aspect ratio. Extra horizontal space that does not fit within the target $width will be cropped off evenly left and right.

As a result, the thumbnail is usually a good representation of the source image.

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