Image Processing (ImageMagick)

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User Contributed Notes 3 notes

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16
mlong-php at mlong dot us
17 years ago
Here is an example on how to take an image that is already in a string (say, from a database), and resize it, add a border, and print it out. I use this for showing reseller logos

// Decode image from base64
$image=base64_decode($imagedata);

// Create Imagick object
$im = new Imagick();

// Convert image into Imagick
$im->readimageblob($image);

// Create thumbnail max of 200x82
$im->thumbnailImage(200,82,true);

// Add a subtle border
$color=new ImagickPixel();
$color->setColor("rgb(220,220,220)");
$im->borderImage($color,1,1);

// Output the image
$output = $im->getimageblob();
$outputtype = $im->getFormat();

header("Content-type: $outputtype");
echo $output;
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0
Eero Niemi (eero at eero dot info)
16 years ago
To load image (usually vector image, like PDF) with larger resolution than image's default is, you have to set resolution before reading the file, like this:

<?php
$im
= new Imagick();
$im->setResolution( 300, 300 );
$im->readImage( "test.pdf" );
?>
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-1
carlosvanhalen7 at gmail dot com
11 years ago
Here's a handy function that finds the first occurrence of a specific pixel. You can set the tolerance of the color you are looking for, or set it to 0 if want an exact match

<?php

function findPixel($img, $r, $g, $b, $tolerance=5)
{
$original_ = new Imagick($img);
$height = 0;
$width = 0;
list(
$width, $height) = getimagesize($img);
$matrix_org = array();
$matrix_mrk = array();

for(
$x = 0 ; $x < $width ; $x++){
$matrix_org[$x] = array();
$matrix_mrk[$x] = array();
}

for(
$x = 0 ; $x < $width ; $x++ )
{
for(
$y = 0 ; $y < $height ; $y++ ){
$matrix_org[$x][$y] = $original_->getImagePixelColor($x, $y)->getColorAsString();
$colors = preg_replace('/[^-,0-9+$]/', '', $matrix_org[$x][$y]);
$colors = explode(',', $colors);
$r_org = $colors[0];
$g_org = $colors[1];
$b_org = $colors[2];

if( (
$r <= ($r_org+$tolerance) && $r >= ($r_org - $tolerance) )
&& (
$g <= ($g_org+$tolerance) && $g >= ($g_org - $tolerance) )
&& (
$b <= ($b_org+$tolerance) && $b >= ($b_org - $tolerance) ) )
{
return array(
$x, $y );
}
}
}

return
false;
}

?>
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