Question

尝试为jpg图像添加透明的PNG水印，如果我在本地主机或生产服务器上，我会得到不同的结果。

这是结果......

在我的本地主机上（PHP版本5.6.24）

在生产服务器上（PHP版本5.5.9-1ubuntu4.21）

我甚至不知道该怎么称这个蓝色变成粉红色的问题并且徽标没有正确呈现......

代码如下：

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

我错过了什么？这让我疯了！

Answer 1

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，而且有点像Esko所说的那样：

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。

Answer 2

我有同样的问题。 Ubuntu中的imageScale函数似乎将绿色和蓝色变为粉红色。解决方案可以是使用imagecopyresampled和imagecreatetruecolor。然而，这种解决方案的速度要慢一些。

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

2 个答案: