How to use the GD2 function to add text to pictures (Typical application tutorial of PHP graphics and images 2)

How to use the GD2 function to add text to pictures (Typical application tutorial of PHP graphics and images 2)

The GD library in PHP supports Chinese, but it must It needs to be transmitted in UTF-8 encoding format. If you use the imagesString() function to draw Chinese characters directly, garbled characters will appear. This is because GD2 can only accept UTF-8 encoding format for Chinese, and uses English fonts by default, so it needs to be output. For Chinese strings, you must transcode the Chinese strings and set the font used for the Chinese strings. Otherwise, the output will only be garbled characters!

In the previous article "Detailed explanation of creating images, colors and filling backgrounds (Typical application tutorial of PHP graphics images 1)", we introduced the creation of images, colors and filling , these are the necessary first steps no matter what kind of image you create, so today we will introduce to you how to add text to the picture!

When we add the text we want on the required picture, then we have to use the imagettftext() function. Let’s first look at the syntax format of this function:

array imagettftext ( resource $image , float $size , float $angle , int $x , int $y , int $color, string $fontfile , string $text )

Next we use the imagettftext() function to add text to the image. The specific development steps are as follows:

1. Define the type of output image through the header() function.

2. Use the imagecreatefromjpeg() function to create a picture.

3. Set the output font color through the imagecolorallocate() function.

4. Define the font used for output Chinese strings.

5. Add text to the image through the imagettftext() function.

6. Create the image and then arm the resource.

The specific code is as follows:

<?php
header("Content-Type:text/html; charset=utf-8");
header(&#39;Content-type: image/png&#39;);// 告诉浏览器，这个文件，是一个png图片
$image = imagecreatefromjpeg("upfile/php.jpg");// 创建图像
// 填充颜色 - ps里的点击画布填色
$image_cololr =  imagecolorallocate($image, 149, 188, 205);
imagefill($image, 0, 0,$image_cololr);
$black = imagecolorallocate($image,  105, 105, 105);//文字颜色
imagettftext($image, 21, 0, 70, 220, $black, "simhei.ttf", "php中文网 m.sbmmt.com");// 设置中文文字
imagepng($image);// 生成图片
imagedestroy($image);// 销毁图片， 释放内存
?>

The output result is as follows:

Explanation:

Tips: Apply this method to create an electronic photo album!

That’s it for adding text to pictures. Below we will introduce the use of images to generate verification codes. For details, please read "Using image processing technology to generate verification codes (typical of PHP graphics and images). Application tutorial 3)》!

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