jpg文件上的php gd image png watermark会产生奇怪的结果

2019年7月3日 146次阅读

试图为jpg图像添加透明的PNG水印,如果我在localhost或生产服务器上,我会得到不同的结果.

这是结果……

在我的localhost上(PHP版本5.6.24)
《jpg文件上的php gd image png watermark会产生奇怪的结果》

在生产服务器上(PHP版本5.5.9-1ubuntu4.21)
《jpg文件上的php gd image png watermark会产生奇怪的结果》

我甚至不知道该怎么称为蓝色变粉红色这个问题并且徽标没有正确呈现…

代码是这样的：

function getBrightness($gdHandle) {
$width = imagesx($gdHandle);
$height = imagesy($gdHandle);

$totalBrightness = 0;

for ($x = 0; $x < $width; $x++) {
    for ($y = 0; $y < $height; $y++) {
        $rgb = imagecolorat($gdHandle, $x, $y);

        $red = ($rgb >> 16) & 0xFF;
        $green = ($rgb >> 8) & 0xFF;
        $blue = $rgb & 0xFF;

        $totalBrightness += (max($red, $green, $blue) + min($red, $green, $blue)) / 2;
    }
}

  //  imagedestroy($gdHandle);

return ($totalBrightness / ($width * $height)) / 2.55;
}

function render_text_on_gd_image(&$source_gd_image, $text, $font, $size, $color, $opacity, $rotation, $bpx, $bpy, $wnewx) {

$source_width = imagesx($source_gd_image);
$source_height = imagesy($source_gd_image);
$bb = imagettfbbox($size, $rotation, $font, $text);
$x0 = min($bb[0], $bb[2], $bb[4], $bb[6]);
$x1 = max($bb[0], $bb[2], $bb[4], $bb[6]);
$y0 = min($bb[1], $bb[3], $bb[5], $bb[7]);
$y1 = max($bb[1], $bb[3], $bb[5], $bb[7]);
$bb_width = abs($x1 - $x0);
$bb_height = abs($y1 - $y0);

$alpha_color = imagecolorallocatealpha(
    $source_gd_image,
    hexdec(substr($color, 0, 2)),
    hexdec(substr($color, 2, 2)),
    hexdec(substr($color, 4, 2)),
    127 * (100 - $opacity) / 100
);
return imagettftext($source_gd_image, $size, $rotation, $bpx + $wnewx/2 - $bb_width/2 , $bpy, $alpha_color, $font, $text);
}


$val = array();

//$val["displayName"] = "Administrador";
$val["displayName"] = "Afonso Ferreira Gomes";

$val["relFile"] = "imagem.jpg";

list($val["width_original"], $val["height_original"]) = getimagesize($val["relFile"]);

if ($val["width_original"] > $val["height_original"] && $val["width_original"] >= 1200) {

    $val["height_resized"] = $val["height_original"] * (1200/$val["width_original"]);
    $val["width_resized"]  = 1200;

}  elseif ($val["height_original"] > $val["width_original"] && $val["height_original"] >= 1200) {

    $val["height_resized"] = 1200;
    $val["width_resized"]  = (1200/$val["height_original"]) * $val["width_original"];

} else {

    $val["height_resized"] = $val["height_original"];
    $val["width_resized"]  = $val["width_original"];

}

$i = imagecreatefromjpeg($val["relFile"]);

$i = imagescale($i, $val["width_resized"], $val["height_resized"]);

$val["width_new"] = imagesx($i);

$val["height_new"] = imagesy($i);


if ($val["width_new"] < $val["height_new"]) {

    $val["portait"] = true;
    $val["smallest"] = $val["width_new"];

} else {

    $val["portait"] = false;
    $val["smallest"] = $val["height_new"];

}


/* GERAR WATERMARK LOGOTIPO */
$val["racio"] = 0.20;
$val["marLeft"] = 40;
$val["marBottom"] = 40;
$val["bright"] = getBrightness($i);


if ($val["bright"] < 30) {

    $val["opacidade"] = 20;

} else {

    $val["opacidade"] = 40;

}

$w = imagecreatefrompng("jbw_260_40.png");

if ($val["portait"]) {

    $val["water_width"] = $val["width_new"] * $val["racio"];
    $val["water_height"] = $val["width_new"] * $val["racio"];

} else {

    $val["water_width"] = $val["height_new"] * $val["racio"];
    $val["water_height"] = $val["height_new"] * $val["racio"];

}

$wnew = imagescale($w, $val["water_width"], $val["water_height"]);

$val["water_width"] = imagesx($wnew);
$val["water_height"] = imagesy($wnew);

/* GERAR WATERMARK TEXTO AUTOR */
if ($val["displayName"] == "Administrador") {
    $val["autor"] = "";
    $val["marBottom"] = 20;
    $val["marLeft"] = 20;
} else {
    $val["autor"] = $val["displayName"];
}


// PRIMEIRO E ULTIMO NOME SÓ!!
$autorNomes = explode(" ", $val["autor"]);

if (count($autorNomes) >= 2) {
    $val["autor"] = $autorNomes[0] . " " . $autorNomes[count($autorNomes) - 1];
} else {
    $val["autor"] = $autorNomes[0];
}

$font = "../font/Montserrat.ttf";
$color = "FFFFFF";

$flagSize = false;

$val["fontSize"] = 12;

for ($size = 7; $size <= 50; $size += 0.5) {

    $bb = imagettfbbox($size, 0, $font, $val["autor"]);
    $x0 = min($bb[0], $bb[2], $bb[4], $bb[6]);
    $x1 = max($bb[0], $bb[2], $bb[4], $bb[6]);
    $y0 = min($bb[1], $bb[3], $bb[5], $bb[7]);
    $y1 = max($bb[1], $bb[3], $bb[5], $bb[7]);

    $val["bbox_width"] = abs($x1 - $x0);
    $val["bbox_height"] = abs($y1 - $y0);

    if (($val["bbox_width"] >= $val["water_width"] && !$flagSize) || $size == 50) {
        $val["fontSize"] = $size;
        $flagSize = true;
        break;
    }
}

$val["posY_water"] = $val["height_new"] - $val["water_height"] - $val["marBottom"];
$val["posY_text"] = $val["height_new"] - $val["marBottom"] + $val["bbox_height"] - 5;

imagecopy($i, $wnew, $val["marLeft"],  $val["posY_water"] , 0, 0, $val["water_width"], $val["water_height"]);

render_text_on_gd_image($i, $val["autor"], $font, $val["fontSize"], $color, $val["opacidade"] ,0 , $val["marLeft"]  , $val["posY_text"], $val["water_width"]);


// echo "<pre>"; print_r($val); echo "</pre>"; die;

/* OUTPUT IMAGEM E LIMPA BUFFER */
header('Content-type: image/png');

imagepng($i);
imagedestroy($i);
imagedestroy($w);

这是localhost和生产服务器的phpinfo的gd部分
《jpg文件上的php gd image png watermark会产生奇怪的结果》

我错过了什么？这让我疯了！

最佳答案 这些问题几乎总是反对源或目标的alpha通道,而不是保留或输出不是真正的颜色.

尝试使用imagesavealpha()函数并在PHP文档的注释中搜索“alpha”,因为有很多人都有类似问题的解决方案.

这条评论可能会有所帮助,有点像Esko所说：

http://php.net/manual/en/function.imagecreatefrompng.php#90364

基本上它使用imagecreatetruecolor()将图像复制到缓冲区.

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