Imagick::thumbnailImage

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

Imagick::thumbnailImage — Changes the size of an image

Описание

bool Imagick::thumbnailImage ( int $columns , int $rows [, bool $fit ] )

Внимание

К настоящему времени эта функция еще не была документирована; для ознакомления доступен только список аргументов.

Changes the size of an image to the given dimensions and removes any associated profiles. The goal is to produce small low cost thumbnail images suited for display on the Web. If TRUE is given as a third parameter then columns and rows parameters are used as maximums for each side. Both sides will be scaled down until the match or are smaller than the parameter given for the side.

Список параметров

columns: Image width
rows: Image height
fit: Whether to force maximum values

Возвращаемые значения

Returns TRUE on success.

Errors/Exceptions

Throws ImagickException on error.

Коментарии

Sep 11

Автор: raybdbomb . gmail


As noted here

ref.imagick

With either of the params as 0, the aspect ratio is maintained.

2007-09-11 02:18:20

http://php5.kiev.ua/manual/ru/function.imagick-thumbnailimage.html

Oct 17

Автор: sgarner at expio dot co dot nz


With $fit == true, the image is resized proportionally so that its _smallest_ dimension matches the width or height specified, NOT both.



For example, if you say thumbnailImage(400, 400, true), on an image of 1600x800, it will be resized to 800x400, NOT 400x200 as you might expect.



The solution is to compare the original image's dimensions to the specified dimensions, and substitute zero for the smaller dimension, and set $fit = false.



i.e.: thumbnailImage(400, 0, false) would resize that 1600x800 image to 400x200.

2007-10-17 08:11:56

http://php5.kiev.ua/manual/ru/function.imagick-thumbnailimage.html

Jun 09

Автор: n-sw-bit at ya dot ru


If you want to resize your picture to fit smallest parameter:



$fitbyWidth = (($maxWidth/$w)<($maxHeight/$h)) ?true:false;



if($fitbyWidth){

    $im->thumbnailImage($maxWidth, 0, false);

}else{

    $im->thumbnailImage(0, $maxHeight, false);

}

2008-06-09 19:48:24

http://php5.kiev.ua/manual/ru/function.imagick-thumbnailimage.html

Jul 02

Автор: Anonymous


Here is a function to calculate the new dimensions of a thumbnail, to fit within the given dimensions on both sides.



<?php

/**

 * Calculate new image dimensions to new constraints

 *

 * @param Original X size in pixels

 * @param Original Y size in pixels

 * @return New X maximum size in pixels

 * @return New Y maximum size in pixels

 */

function scaleImage($x,$y,$cx,$cy) {

    //Set the default NEW values to be the old, in case it doesn't even need scaling

    list($nx,$ny)=array($x,$y);

    

    //If image is generally smaller, don't even bother

    if ($x>=$cx || $y>=$cx) {

            

        //Work out ratios

        if ($x>0) $rx=$cx/$x;

        if ($y>0) $ry=$cy/$y;

        

        //Use the lowest ratio, to ensure we don't go over the wanted image size

        if ($rx>$ry) {

            $r=$ry;

        } else {

            $r=$rx;

        }

        

        //Calculate the new size based on the chosen ratio

        $nx=intval($x*$r);

        $ny=intval($y*$r);

    }    

    

    //Return the results

    return array($nx,$ny);

}

?>



Use it like this:



<?php

//Read original image and create Imagick object

$thumb=new Imagick($originalImageFilename);



//Work out new dimensions

list($newX,$newY)=scaleImage(

        $thumb->getImageWidth(),

        $thumb->getImageHeight(),

        $newMaximumWidth,

        $newMaximumHeight);



//Scale the image

$thumb->thumbnailImage($newX,$newY);



//Write the new image to a file

$thumb->writeImage($thumbnailFilename);

?>

2008-07-02 14:15:03

http://php5.kiev.ua/manual/ru/function.imagick-thumbnailimage.html

Oct 29

Автор: jarrod at jarrodchristman dot com


Even though thumbnailImage is meant to produce the smallest file size image possible, i found it didn't. I put together this code and bordering different compression settings, found it produced the smallest file size:



<?php

// Max vert or horiz resolution

$maxsize=550;



// create new Imagick object

$image = new Imagick('input_image_filename_and_location');



// Resizes to whichever is larger, width or height

if($image->getImageHeight() <= $image->getImageWidth())

{

// Resize image using the lanczos resampling algorithm based on width

$image->resizeImage($maxsize,0,Imagick::FILTER_LANCZOS,1);

}

else

{

// Resize image using the lanczos resampling algorithm based on height

$image->resizeImage(0,$maxsize,Imagick::FILTER_LANCZOS,1);

}



// Set to use jpeg compression

$image->setImageCompression(Imagick::COMPRESSION_JPEG);

// Set compression level (1 lowest quality, 100 highest quality)

$image->setImageCompressionQuality(75);

// Strip out unneeded meta data

$image->stripImage();

// Writes resultant image to output directory

$image->writeImage('output_image_filename_and_location');

// Destroys Imagick object, freeing allocated resources in the process

$image->destroy();



?>



I found setCompression to not function at all and had to use setImageCompression. The stripImage call is needed and strips out unneeded meta data. You can choose whatever filter you want, but i found lanczos to be the best for image reduction, though it is more computationally heavy.