Question

所以我将三个图像透明并将它们叠在一起。我在这篇文章中跟踪了示例代码：Remove Image background with php and save transparent png但是由于图像没有完全统一的单色背景，因此提取的图像周围都有丑陋的白色边框。尽管它们可能看起来是白色的，但事实上通常会有不同的灰色或甚至蓝色。

所以现在我想在图像中删除这些丑陋的白色边框。我在网上找到了一个解决问题的java函数：http://www.logikdev.com/2011/10/05/make-image-backgrounds-transparent-with-tolerance/这是他使用的代码：

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);

}

但我不知道如何用php做到这一点。谁可以帮助我？

Answer 1

您可以使用IMagick::paintTransparentImage

此方法的签名如下

 bool Imagick::paintTransparentImage ( mixed $target , float $alpha , float $fuzz );

一个示例用例是：

$im = new Imagick("test.jpg");
$im->paintTransparentImage(($im->getImagePixelColor(0, 0), 0, 1200));
$im->setImageFormat("png");
$im->writeImage("test.png");

您必须使用$ fuzz参数播放arround才能获得您想要的结果。

Answer 2

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]);

PHP - 使图像背景透明，具有公差

2 个答案: