ImageMagick Transparent PNG Background

问题:

I am trying to take this image, which I converted to a .png file and then want to remove the white background to make it transparent.

I have tried running the following but haven't had any luck.

    $strInputFile = 'car.png';
    $execScript = '/usr/local/bin/convert '.$strInputFile.' ';
    $execScript .= "-transparent white car-new.png"; 
    $output = shell_exec($execScript);

Am I doing something wrong? The new file gets created, but still has the white background.

回答1:

Similar problem with php imagick:

When converting SVG to transparent PNG, dont forget to put this BEFORE $imagick->readImageBlob():

$imagick->setBackgroundColor(new ImagickPixel('transparent'));

回答2:

As the image is a JPEG, which is subject to losses and slight colour inaccuracies, the whites in your image are not actually 100% pure white. ImageMagick has a way of dealing with this through the -fuzz setting which allows a degree of fuzziness, or a range of allowable error, when specifying colours.

The correct incantation here is:

convert car.jpg -fuzz 10% -transparent white car.png

回答3:

Try the following code:

$strInputFile = 'car.png';
$target = 'car_transparent.png';
$im = new Imagick($strInputFile);
$im->paintTransparentImage($im->getImageBackgroundColor(), 0, 10000);
$im->setImageFormat('png');
$im->writeImage($target);
$im->destroy();

回答4:

Did you mean to use -transparency rather than -transparent?

回答5:

The background of your image is not white (I mean 0xFFFFFF), it's 0xFEFEFE. Try:

$execScript .= "-transparent #FEFEFE car-new.png"; 

回答6:

If you're not making a Shell script, then try this:

$ convert -transparency white car.png car-new.png

This should work in a generic terminal. If it doesn't, let me know. Hope it helps!