imagemagick skew or distort an image - php

Question

Well how could I change the before image to the after image by using imagemagick?
Is it the -skew command or the -distort, and how can I use it preferably in typo3 and php?
Any help is appreciated!

Answer 1

Using Imagemagick with php and the command line:
// Working on the original image size of 400 x 300
$cmd = "before.jpg -matte -virtual-pixel transparent".
" +distort Perspective \"0,0 0,0 400,0 400,22 400,300 400,320 0,300 0,300 \" ";
exec("convert $cmd perspective.png");
Note:
1/ This is for later versions of Imagemagick - the perspective operator has change.
2/ You need to use +distort not -distort as the image is larger than the initial image boundrys.
Examples of Imagemagick with php usage on my site http://www.rubblewebs.co.uk/imagemagick/operator.php

Answer 2

I think what you're looking for is the Imagick::shearImage function. This creates a checkerboard square and distorts it into a parallelogram (save this as a PHP file and open in your browser to see):
<?php
$im = new Imagick();
$im->newPseudoImage(300, 300, "pattern:checkerboard");
$im->setImageFormat('png');
$im->shearImage("transparent", 0, 10);
header("Content-Type: image/png");
echo $im;
?>
Within a larger script, to shear an image named myimg.png and save it as myimg-sheared.png, you can use:
$im = new Imagick("myimg.png");
$im->shearImage("transparent", 0, 10);
$im->writeImage("myimg_sheared.png");
If shearImage isn't versatile enough, you can try the Imagick::DISTORTION_PERSPECTIVE method via the Imagick::distortImage function.

Answer 3

Perspective distortion should give you what you want. Example:
convert original.png -matte -virtual-pixel white +distort Perspective '0,0,0,0 0,100,0,100 100,100,90,110 100,0,90,5' distorted.png
In TYPO3 you could apply it by (ab)using the SCALE object of the GIFBUILDER. Example:
temp.example = IMAGE
temp.example {
file = GIFBUILDER
file {
format = jpg
quality = 100
maxWidth = 9999
maxHeight = 9999
XY = [10.w],[10.h]
10 = IMAGE
10.file = fileadmin/original.png
20 = SCALE
20 {
params = -matte -virtual-pixel white +distort Perspective '0,0,0,0 0,100,0,100 100,100,90,110 100,0,90,5'
}
}
}