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imagecolortransparent
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imagecolortransparent

Name

imagecolortransparent — Sets a color as transparent.

Synopsis

int imagecolortransparent(image, color); int image: Image identifier int color: Specified color

Returns

Index of transparent color

Description

Sets the portions of an image containing the specified color to be transparent. Using a combination of imagecolorexact() , imagecolorclosest() , and/or imagecolorat() , transparent images can be built on the fly without knowing the exact background color. This depends on the layout of the original image, of course.

Example

Example 403. Create a transparent image

header("Content-type: image/png");
$im = imagecreatefrompng("test_image.png");
$bg_color = imagecolorat($im,1,1);
imagecolortransparent($im, $bg_color);
imagepng($im);
imagedestroy($im);

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