The color value (3rd argument) for transparency is "none".
(PECL imagick 2, PECL imagick 3)
Imagick::newImage — Creates a new image
Creates a new image and associates ImagickPixel value as background color
colsColumns in the new image
rowsRows in the new image
backgroundThe background color used for this image
formatImage format. This parameter was added in Imagick version 2.0.1.
Returns true on success.
Throws ImagickException on error.
| Version | Description |
|---|---|
| PECL imagick 2.1.0 | Now allows a string representing the color as the third parameter. Previous versions allow only an ImagickPixel object. |
Example #1 Using Imagick::newImage():
Create a new image and display it.
<?php
$image = new Imagick();
$image->newImage(100, 100, new ImagickPixel('red'));
$image->setImageFormat('png');
header('Content-type: image/png');
echo $image;
?>The color value (3rd argument) for transparency is "none".As it isn't obvious, the cols and rows arguments correspond to the width and height of the new image, expressed in pixels. Example #1 would generate a 100 pixel by 100 pixel image.It's not obvious and may be related only to some specific versions of ImageMagick (tested only for 6.7.7 and 6.8.9), but $cols and $rows must be a positive non-zero value.
<?php
$image = new Imagick();
$image->newImage(0, 100, new ImagickPixel('red'));
$image->setImageFormat('png');
file_put_contents('image.png', $image);
?>
In this case imagemagick will crash without throwing any exception and you'll get something along the lines (in your apache error log or console output):
unable to acquire cache view `No such file or directory' @ fatal/cache-view.c/AcquireAuthenticCacheView/121.
This might be the case when you calculate $cols and $rows (say, based on user input and predefined target image DPI):
<?php
$image = new Imagick();
$img->newImage($userInput->getWidth() * $defaultPpi, $userInput->getHeight() * $defaultPpi, new ImagickPixel('white'));
?>
In this case if user requested image with 0.006 width (in inches), the code would work for $defaultPpi = 300 ppi, but would crash for
$defaultPpi = 72 ppi