A summary of how php generates a QR code with a logo, a summary of phplogo

1. Class libraries used

1. phpqrcode (php library)

2. qrcode.js (javascript library)

2. Use of phpqrcode

Only uses the PHP class library, that is, the generation of QR codes is operated in the background. Because you want to generate a QR code with a logo in the background, you must first upload the logo image to the server (I used webuploader for uploading)

How to use phpqrcode:

First download phpqrcode: http://phpqrcode.sourceforge.net/

Then remember to introduce the phpqrcode.php file before using it

$value = $url;//二維碼內(nèi)容 
$errorCorrectionLevel = 'L';//設(shè)置容錯(cuò)級(jí)別 
$matrixPointSize = $size;//生成圖片大小 
QRcode::png($value, 'public_files'.DIRECTORY_SEPARATOR .'code'.DIRECTORY_SEPARATOR .'qrcode.png', $errorCorrectionLevel, $matrixPointSize, 2);//生成二維碼圖片 無logo
$logo = $tar_path;//上傳至服務(wù)器的logo圖片 
$QR = 'public_files'.DIRECTORY_SEPARATOR .'code'.DIRECTORY_SEPARATOR .'qrcode.png';//已經(jīng)生成的原始二維碼圖
 
if ($logo !== FALSE) {
  $QR = imagecreatefromstring(file_get_contents($QR));
  $logo = imagecreatefromstring(file_get_contents($logo));
  $QR_width = imagesx($QR);//二維碼圖片寬度
  $QR_height = imagesy($QR);//二維碼圖片高度
  $logo_width = imagesx($logo);//logo圖片寬度
  $logo_height = imagesy($logo);//logo圖片高度
  $logo_qr_width = $QR_width / 5;
  $scale = $logo_width/$logo_qr_width;
  $logo_qr_height = $logo_height/$scale;
  $from_width = ($QR_width - $logo_qr_width) / 2;
  imagecopyresampled($QR, $logo, $from_width, $from_width, 0, 0, $logo_qr_width,
    $logo_qr_height, $logo_width, $logo_height);
}
$name = time();
imagepng($QR, 'public_files'.DIRECTORY_SEPARATOR .'code'.DIRECTORY_SEPARATOR .$name.'.png');//輸出帶logo的二維碼圖片

3. Use of qrcode.js

Use qrcode.js to directly generate QR codes on the front end. You first need to download jquery.qrcode.js

The use of qrcode is also very simple:

var length = size*80;//設(shè)置二維碼大小
length = parseInt(length);
$("#code_img").qrcode({ //code_img是一個(gè)img標(biāo)簽的id
  render : "canvas",  //設(shè)置渲染方式，有table和canvas，使用canvas方式渲染性能相對(duì)來說比較好
  text : url,  //掃描二維碼后顯示的內(nèi)容,可以直接填一個(gè)網(wǎng)址，掃描二維碼后自動(dòng)跳向該鏈接
  width : length,       //二維碼的寬度
  height : length,
  background : "#ffffff",    //二維碼的后景色
  foreground : "#000000",    //二維碼的前景色
  src: $('#image').attr('src')       //二維碼中間的圖片
});

After introducing jquery.qrcode.js, write this js code yourself. After execution, the QR code can be displayed and processed

Mainly the logo reference format in the middle of the QR code. Generally, there are two formats for taking local images: one is the local URL, and the other is to convert the image into base64 format

At first I tried the local URL format to reference images, but found that I could only reference images in the same directory as the js file, so the local URL format was not supported, so I adopted the latter method.

Use

To upload and select a local image, and then take its base64 format

var input = document.getElementById("file_input");
 
if(typeof FileReader==='undefined'){
  input.setAttribute('disabled','disabled');
}else{
  input.addEventListener('change',readFile,false);
}
 
function readFile(){
  var file = this.files[0];
  if(!/image\/\w+/.test(file.type)){
    alert("文件必須為圖片！");
    return false;
  }
  var reader = new FileReader();
  reader.readAsDataURL(file);
  reader.onload = function(e){
    $('#image').attr('src',this.result);//image為img標(biāo)簽的id
  }
}

Read the file as a string of Data URL strings, and read the small file directly into the page with a URL address in a special format. This special format is base64

3. Comparison between the two class libraries

Two class libraries, one operates in the background and the other operates directly in the front end.

phpqrcode generates QR codes and operates in the background, and the generated images are saved on the server. Generally, the generated QR code is saved directly to the local and then used directly. It is rare to go to the server to obtain it for a second time. Therefore, using phpqrcode will cause the images in the server to accumulate, occupying unnecessary space, and deleting them will also cost extra money. overhead. So using phpqrcode is not suitable for this QR code generation tool. Moreover, uploading images will also incur extra overhead

qrcode.js operates directly on the front-end, uploads images and saves them directly in the browser, and generates QR codes directly on the front-end without any background interference. This reduces unnecessary overhead and does not cause image corruption on the server. Stack up and take up unnecessary space.

Articles you may be interested in:

• Several ways to generate QR codes with php and their use examples
• How to create your own QR code for images with php in the middle
• Two ways to use PHP to generate QR codes (with logo images)
• Create QR codes with website LOGO in the middle through the QRCode class library under PHP
• Generate with php Solutions to Chinese garbled characters when QR codes appear
• Generate business cards, links and other QR codes based on JavaScript
• Summary of JavaScript-generated QR code pictures