How to write text in php pictures

php Writing text on a picture is equivalent to adding a text watermark to the picture. Generally, when uploading a picture, the watermark is usually a text or picture logo watermark. Let’s take a look at the two adding methods. .

1. Text watermark

Text watermark is to add text to the picture. It mainly uses the imagefttext method of the gd library and requires a font file.

$dst_path = 'dst.jpg';
//创建图片的实例
$dst = imagecreatefromstring(file_get_contents($dst_path));
//打上文字
$font = './simsun.ttc';//字体路径
$black = imagecolorallocate($dst, 0x00, 0x00, 0x00);//字体颜色
imagefttext($dst, 13, 0, 20, 20, $black, $font, '快乐编程');
//输出图片
list($dst_w, $dst_h, $dst_type) = getimagesize($dst_path);
switch ($dst_type) {
    case 1://GIF
        header('Content-Type: image/gif');
        imagegif($dst);
        break;
    case 2://JPG
        header('Content-Type: image/jpeg');
        imagejpeg($dst);
        break;
    case 3://PNG
        header('Content-Type: image/png');
        imagepng($dst);
        break;
    default:
        break;
}
imagedestroy($dst);

Create a new picture, and then print the text watermark:

// imagecreatefromstring
// imageCreateFromPng  Create a new image from file or URL   创建图片对象
// Create a 300x100 image，新创建一张图片
$im = imagecreatetruecolor(500, 300);
// set color
$red = imagecolorallocate($im, 0xFF, 0x00, 0x00);
$black = imagecolorallocate($im, 0x00, 0x00, 0x00);
// Make the background red
// function imagefilledrectangle ($image, $x1, $y1, $x2, $y2, $color) {}
imagefilledrectangle($im, 0, 0, 300, 100, $red);
// Path to our ttf font file
$font_file = './font/Arial.ttf';
// imagefttext ($image, $size, $angle, $x, $y, $color, $fontfile, $text, $extrainfo = null )
// Draw the text 'PHP Manual' using font size 13
imagefttext($im, 13, 0, 150, 50, $black, $font_file, 'PHP Manual');
// Output image to the browser
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
clipboard.png

The rendering is as follows:

2. Picture Watermark

Picture watermark is to add one picture to another picture, mainly using the imagecopy and imagecopymerge of the gd library.

$dst_path = 'myimage.jpg';
$src_path = 'http://www.logodashi.com/FileUpLoad/inspiration/636003768803214440.jpg';
//创建图片的实例
$dst = imagecreatefromstring(file_get_contents($dst_path));
$src = imagecreatefromstring(file_get_contents($src_path));
//获取水印图片的宽高
list($src_w, $src_h) = getimagesize($src_path);
//将水印图片复制到目标图片上，最后个参数50是设置透明度，这里实现半透明效果
imagecopymerge($dst, $src, 10, 10, 0, 0, $src_w, $src_h, 30);
//如果水印图片本身带透明色，则使用imagecopy方法
// imagecopy($dst, $src, 10, 10, 0, 0, $src_w, $src_h);
//输出图片
list($dst_w, $dst_h, $dst_type) = getimagesize($dst_path);
switch ($dst_type) {
    case 1://GIF
        header('Content-Type: image/gif');
        imagegif($dst);
        break;
    case 2://JPG
        header('Content-Type: image/jpeg');
        imagejpeg($dst);
        break;
    case 3://PNG
        header('Content-Type: image/png');
        imagepng($dst);
        break;
    default:
        break;
}
imagedestroy($dst);
imagedestroy($src);

Rendering:

3. Other functions related to image processing

/*
 *返回图像的大小及图像类型
// Get the size of an image
$size = getimagesize("http://image18-c.poco.cn/mypoco/myphoto/20160901/20/17857099520160901203311082.jpg?750x956_120");
print_r($size);
// 打印结果
Array
(
    [0] => 750
    [1] => 956
    [2] => 2
    [3] => width="750" height="956"
    [bits] => 8
    [channels] => 3
    [mime] => image/jpeg
)
*/
/**
 * imagecopy — 拷贝图像的一部分
 */
// bool imagecopy ( resource $dst_im , resource $src_im , int $dst_x , int $dst_y , int $src_x , int $src_y , int $src_w , int $src_h )
// 将 src_im 图像中坐标从 src_x，src_y 开始，宽度为 src_w，高度为 src_h 的一部分拷贝到 dst_im 图像中坐标为 dst_x 和 dst_y 的位置上。
/*
 *
 * http://php.net/manual/zh/function.imagecopymerge.php
 *imagecopymerge — 拷贝并合并图像的一部分
 *bool imagecopymerge ( resource $dst_im , resource $src_im , int $dst_x , int $dst_y , int $src_x , int $src_y , int $src_w , int $src_h , int $pct )
 *
 *
 */

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