向图片任意位置添加logo

这个的原理是把logo‘画’图片的指定位置.
步骤如下:
1.获取图片和logo的基本信息
getimagesize

2.判断图片资源类型并创建对应图片资源
getPicType (自定义函数)

3.获取logo的位置坐标
getLocal (自定义函数)

4.把logo画上去
imagecopyresampled

5.输出图像
outputImage (自定义函数)

6.释放图片资源
imagedestroy

效果如图:

代码如下:

<code><span>/**
 *<span> @function</span> 向图像中添加logo
 *<span> @param</span> $picname
 *<span> @param</span> $logo
 *<span> @param</span> int $local logo添加的位置:1:左上角,2:右上角,3:左下角,4:右下角,5:中上,6:中间,7:中下
 * <span> @param</span> string $pre
 *<span> @return</span> 返回一个新的图片名
 */</span><span><span>function</span><span>addLogo</span><span>(<span>$picname</span>,<span>$logo</span>,<span>$local</span>=<span>"1"</span>,<span>$pre</span>=<span>"l_"</span>)</span>
{</span><span>$picInfo</span> = getimagesize(<span>$picname</span>); <span>//获取图片的基本信息</span><span>$logoInfo</span> = getimagesize(<span>$logo</span>);   <span>//获取logo的基本信息</span><span>$picW</span> = <span>$picInfo</span>[<span>0</span>];<span>//获取pic宽度</span><span>$picH</span> = <span>$picInfo</span>[<span>1</span>];<span>//获取pic高度</span><span>$logoW</span> = <span>$logoInfo</span>[<span>0</span>]; <span>//获取logo宽度</span><span>$logoH</span> = <span>$logoInfo</span>[<span>1</span>]; <span>//获取logo高度</span><span>//获取图片资源类型并创建对应图片资源</span><span>$picim</span> = getPicType(<span>$picInfo</span>[<span>2</span>],<span>$picname</span>);
    <span>$logoim</span> = getPicType(<span>$logoInfo</span>[<span>2</span>],<span>$logo</span>);
    <span>//把logo画上去</span><span>$XY</span> = getLocal(<span>$local</span>,<span>$picW</span>,<span>$picH</span>,<span>$logoW</span>,<span>$logoH</span>);<span>//获取logo的位置坐标</span>
    imagecopyresampled(<span>$picim</span>,<span>$logoim</span>,<span>$XY</span>[<span>0</span>],<span>$XY</span>[<span>1</span>],<span>0</span>,<span>0</span>,<span>$logoW</span>,<span>$logoH</span>,<span>$logoW</span>,<span>$logoH</span>);
    <span>//输出图像</span><span>$newPicName</span> = outputImage(<span>$picname</span>,<span>$pre</span>,<span>$picim</span>);
    <span>//释放图片资源</span>
    imagedestroy(<span>$picim</span>);
    imagedestroy(<span>$logoim</span>);
    <span>return</span><span>$newPicName</span>;
}

<span>/**
 *<span> @function</span> 获取对应位置的左上角坐标
 *<span> @param</span> $local  位置
 *<span> @param</span> $picW   图片宽
 *<span> @param</span> $picH   图片高
 *<span> @param</span> $logoW  logo宽
 *<span> @param</span> $logoH  logo高
 *<span> @return</span> 返回宽高数组
 */</span><span><span>function</span><span>getLocal</span><span>(<span>$local</span>,<span>$picW</span>,<span>$picH</span>,<span>$logoW</span>,<span>$logoH</span>)</span>
{</span><span>$XY</span> = <span>array</span>();
    <span>switch</span>(<span>$local</span>)
    {
        <span>case</span><span>1</span>:
            <span>$XY</span> = <span>array</span>(<span>0</span>,<span>0</span>);
            <span>break</span>;
        <span>case</span><span>2</span>:
            <span>$XY</span> = <span>array</span>(<span>$picW</span>-<span>$logoW</span>,<span>0</span>);
            <span>break</span>;
        <span>case</span><span>3</span>:
            <span>$XY</span> = <span>array</span>(<span>0</span>,<span>$picH</span>-<span>$logoH</span>);
            <span>break</span>;
        <span>case</span><span>4</span>:
            <span>$XY</span> = <span>array</span>(<span>$picW</span>-<span>$logoW</span>,<span>$picH</span>-<span>$logoH</span>);
            <span>break</span>;
        <span>case</span><span>5</span>:
            <span>$XY</span> = <span>array</span>(<span>$picW</span>/<span>2</span> - <span>$logoW</span>/<span>2</span>,<span>0</span>);
            <span>break</span>;
        <span>case</span><span>6</span>:
            <span>$XY</span> = <span>array</span>(<span>$picW</span>/<span>2</span> - <span>$logoW</span>/<span>2</span>,<span>$picH</span>/<span>2</span> - <span>$logoH</span>/<span>2</span>);
            <span>break</span>;
        <span>case</span><span>7</span>:
            <span>$XY</span> = <span>array</span>(<span>$picW</span>/<span>2</span> - <span>$logoW</span>/<span>2</span>,<span>$picH</span>-<span>$logoH</span>);
            <span>break</span>;
        <span>default</span>:
            <span>die</span>(<span>"不支持这个位置的logo添加"</span>);
            <span>break</span>;
    }
    <span>return</span><span>$XY</span>;
}

<span>/**
 * function 判断并返回图片的类型(以资源方式返回)
 *<span> @param</span> int $type 图片类型
 *<span> @param</span> string $picname 图片名字
 *<span> @return</span> 返回对应图片资源
 */</span><span><span>function</span><span>getPicType</span><span>(<span>$type</span>,<span>$picname</span>)</span>
{</span><span>$im</span>=<span>null</span>;
    <span>switch</span>(<span>$type</span>)
    {
        <span>case</span><span>1</span>:  <span>//GIF</span><span>$im</span> = imagecreatefromgif(<span>$picname</span>);
            <span>break</span>;
        <span>case</span><span>2</span>:  <span>//JPG</span><span>$im</span> = imagecreatefromjpeg(<span>$picname</span>);
            <span>break</span>;
        <span>case</span><span>3</span>:  <span>//PNG</span><span>$im</span> = imagecreatefrompng(<span>$picname</span>);
            <span>break</span>;
        <span>case</span><span>4</span>:  <span>//BMP</span><span>$im</span> = imagecreatefromwbmp(<span>$picname</span>);
            <span>break</span>;
        <span>default</span>:
            <span>die</span>(<span>"不认识图片类型"</span>);
            <span>break</span>;
    }
    <span>return</span><span>$im</span>;
}

<span>/**
 * function 输出图像
 *<span> @param</span> string $picname 图片名字
 *<span> @param</span> string $pre 新图片名前缀
 *<span> @param</span> resourse $nim 要输出的图像资源
 *<span> @return</span> 返回新的图片名
 */</span><span><span>function</span><span>outputImage</span><span>(<span>$picname</span>,<span>$pre</span>,<span>$nim</span>)</span>
{</span><span>$info</span> = getimagesize(<span>$picname</span>);
    <span>$picInfo</span> = pathInfo(<span>$picname</span>);
    <span>$newPicName</span> = <span>$picInfo</span>[<span>'dirname'</span>].<span>'/'</span>.<span>$pre</span>.<span>$picInfo</span>[<span>'basename'</span>];<span>//输出文件的路径</span><span>switch</span>(<span>$info</span>[<span>2</span>])
    {
        <span>case</span><span>1</span>:
            imagegif(<span>$nim</span>,<span>$newPicName</span>);
            <span>break</span>;
        <span>case</span><span>2</span>:
            imagejpeg(<span>$nim</span>,<span>$newPicName</span>);
            <span>break</span>;
        <span>case</span><span>3</span>:
            imagepng(<span>$nim</span>,<span>$newPicName</span>);
            <span>break</span>;
        <span>case</span><span>4</span>:
            imagewbmp(<span>$nim</span>,<span>$newPicName</span>);
            <span>break</span>;
    }
    <span>return</span><span>$newPicName</span>;
}</code>

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以上就介绍了 向图片任意位置添加logo，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。