The article introduces the program to generate a png thumbnail with a transparent background in PHP. It is very simple to process this in PHP. We only need to use imagealphablending($thumb,false); and imagesavealpha($thumb,true);. , see the program below.
When generating PNG thumbnails, the background is black. Today I wrote a function to make up for it. The code is very simple, that is, imagealphablending($thumb,false); and imagesavealpha($thumb,true); are very important. The main thing is to save the alpha value of PNG and not lose it.
| 代码如下 | 复制代码 |
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/* *$sourePic:原图路径 * $smallFileName:小图名称 * $width:小图宽 * $heigh:小图高 * 转载注明 www.hzhuti.com */ function pngthumb($sourePic,$smallFileName,$width,$heigh){ $image=imagecreatefrompng($sourePic);//PNG imagesavealpha($image,true);//这里很重要 意思是不要丢了$sourePic图像的透明色; $BigWidth=imagesx($image);//大图宽度 $BigHeigh=imagesy($image);//大图高度 $thumb = imagecreatetruecolor($width,$heigh); imagealphablending($thumb,false);//这里很重要,意思是不合并颜色,直接用$img图像颜色替换,包括透明色; imagesavealpha($thumb,true);//这里很重要,意思是不要丢了$thumb图像的透明色; if(imagecopyresampled($thumb,$image,0,0,0,0,$width,$heigh,$BigWidth,$BigHeigh)){ imagepng($thumb,$smallFileName);} return $smallFileName;//返回小图路径 } pngthumb("a.png", "c.png", 300, 300);//调用 ?> |
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We all used the functions that come with PHP and did not use any third-party programs. Friends in need can take a look.
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