所以我让三个图像透明，并将它们相互叠加。使用php删除图像背景并保存透明png，但由于图像没有完全统一的单色背景，提取的图像周围都有丑陋的白色边框。尽管它们看起来是白色的，但实际上通常有不同深浅的灰色甚至蓝色。
现在我想删除这些丑陋的白色边框在图像中。我在网上找到了一个java函数来解决这个问题:http://www.logikdev.com/2011/10/05/make-image-backgrounds-transparent-with-tolerance/下面是他使用的代码:
private Image makeColorTransparent(final BufferedImage im, final Color color, int tolerance) {
int temp = 0;
if (tolerance < 0 || tolerance > 100) {
System.err.println("The tolerance is a percentage, so the value has to be between 0 and 100.");
temp = 0;
} else {
temp = tolerance * (0xFF000000 | 0xFF000000) / 100;
}
final int toleranceRGB = Math.abs(temp);
final ImageFilter filter = new RGBImageFilter() {
// The color we are looking for (white)... Alpha bits are set to opaque
public int markerRGBFrom = (color.getRGB() | 0xFF000000) - toleranceRGB;
public int markerRGBTo = (color.getRGB() | 0xFF000000) + toleranceRGB;
public final int filterRGB(final int x, final int y, final int rgb) {
if ((rgb | 0xFF000000) >= markerRGBFrom && (rgb | 0xFF000000) <= markerRGBTo) {
// Mark the alpha bits as zero - transparent
return 0x00FFFFFF & rgb;
} else {
// Nothing to do
return rgb;
}
}
};
final ImageProducer ip = new FilteredImageSource(im.getSource(), filter);
return Toolkit.getDefaultToolkit().createImage(ip);
}
但是我不知道如何用php做到这一点。有人能帮我吗?
你可以使用IMagick::paintTransparentImage
这个方法的签名如下
bool Imagick::paintTransparentImage ( mixed $target , float $alpha , float $fuzz );
一个这样的用例是:
$im = new Imagick("test.jpg");
$im->paintTransparentImage(($im->getImagePixelColor(0, 0), 0, 1200));
$im->setImageFormat("png");
$im->writeImage("test.png");
您将不得不使用$fuzz参数来获得您正在寻找的那种结果。
function transparant($url){
$img = urldecode(trim($url));
$imgx = imagecreatefromjpeg($img);
$img_w = imagesx($imgx);
$img_h = imagesy($imgx);
$im = imagecreatetruecolor($img_w, $img_h);
imagesavealpha( $im, true );
$rgb = imagecolorallocatealpha( $im, 0, 0, 0, 127 );
imagefill( $im, 0, 0, $rgb );
$color = imagecolorat( $imgx, 1, 1);
$temp = 0;
$tolerance = 20;
$temp = $tolerance * (0xFF000000 | 0xFF000000) / 100;
$toleranceRGB = abs($temp);
$startcolor = $color - $toleranceRGB;
$endcolor = $color + $toleranceRGB;
for( $x = 0; $x < $img_w; $x++ ) {
for( $y = 0; $y < $img_h; $y++ ) {
$c = imagecolorat( $imgx, $x, $y );
$startcolor."|".$c."|".$endcolor."<br>";
if ($c > $startcolor && $c < $endcolor){}else{
imagesetpixel( $im, $x, $y, $c);
}
}
}
$filename = basename($img);
header('Content-type: image/png');
imagepng($im, null);
imagedestroy($im);
imagedestroy($imgx);
}
transparant([url encoded image]);