How to make QR code transparent in php

Directly make the background of the QR code image transparent(Recommended learning:PHP video tutorial)

//二维码内容 $qrcodeContent = '此处存链接的话，参数不宜过长，否则导致生成二维码时间太长！！！'; //容错级别 $errorCorrectionLevel = 'L'; //生成图片大小 $matrixPointSize = 6; //生成二维码图片 \QRcode::png($qrcodeContent, 'qrcode.png', $errorCorrectionLevel, $matrixPointSize, 2); $QR = 'qrcode.png';//已经生成的原始二维码图 //将二维码背景变透明 $resource = imagecreatefrompng($QR); @unlink($QR); $bgcolor = imagecolorallocate($resource, 255, 255, 255); imagefill($resource, 0, 0, $bgcolor); imagecolortransparent($resource, $bgcolor); imagepng($resource,'qrcode_copy.png'); /*先处理成透明图再进行缩放就不会出现白黑点情况了！！！（至少效果好多了，而先进行缩放再处理背景透明就会出现很多白黑点！）*/ @imagedestroy($resource); //获取对应游戏海报二维码位置 $qrcode_pos = $pos;//$pos = [x,y] //获取对应游戏海报二维码规格 $qrcode_spec = $spec;//$spec = [w,h] $resource = smart_resize_image('qrcode_copy.png', $qrcode_spec[0], $qrcode_spec[1], true); imagepng($resource,'qrcode_'.$gameType.'.png');//存储改变大小后的透明二维码 $qrcode = 'qrcode_'.$gameType.'.png'; //将透明背景的二维码贴到海报图指定位置 $poster_with_qrcode_or_invitedcode_url = waterImage($posterUrl, $qrcode, $qrcode_pos[0], $qrcode_pos[1]); @imagedestroy($resource); @unlink('qrcode_copy.png'); @unlink($qrcode);

The above calling method is as follows:

/** * 调整图片大小并返回图片资源 * @param $file * @param int $width * @param int $height * @param bool $proportional * @return bool|resource * @author zsb */ function smart_resize_image($file, $width = 0, $height = 0, $proportional = false) { if ( $height <= 0 && $width <= 0 ) { return false; } $info = getimagesize($file); $image = ''; $final_width = 0; $final_height = 0; list($width_old, $height_old) = $info; if ($proportional) { if ($width == 0) { $factor = $height/$height_old; }elseif ($height == 0) { $factor = $width/$width_old; }else { $factor = min ( $width / $width_old, $height / $height_old); } $final_width = round ($width_old * $factor); $final_height = round ($height_old * $factor); }else { $final_width = ( $width <= 0 ) ? $width_old : $width; $final_height = ( $height <= 0 ) ? $height_old : $height; } switch ($info[2]) { case IMAGETYPE_GIF: $image = imagecreatefromgif($file); break; case IMAGETYPE_JPEG: $image = imagecreatefromjpeg($file); break; case IMAGETYPE_PNG: $image = imagecreatefrompng($file); break; default: return false; } $image_resized = imagecreatetruecolor( $final_width, $final_height ); if ( ($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG) ) { $trnprt_indx = imagecolortransparent($image); // If we have a specific transparent color if ($trnprt_indx >= 0) { // Get the original image's transparent color's RGB values $trnprt_color = imagecolorsforindex($image, $trnprt_indx); // Allocate the same color in the new image resource $trnprt_indx = imagecolorallocate($image_resized, $trnprt_color['red'], $trnprt_color['green'], $trnprt_color['blue']); // Completely fill the background of the new image with allocated color. imagefill($image_resized, 0, 0, $trnprt_indx); // Set the background color for new image to transparent imagecolortransparent($image_resized, $trnprt_indx); } // Always make a transparent background color for PNGs that don't have one allocated already elseif ($info[2] == IMAGETYPE_PNG) { // Turn off transparency blending (temporarily) imagealphablending($image_resized, false); // Create a new transparent color for image $color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127); // Completely fill the background of the new image with allocated color. imagefill($image_resized, 0, 0, $color); // Restore transparency blending imagesavealpha($image_resized, true); } } imagecopyresampled($image_resized, $image, 0, 0, 0, 0, $final_width, $final_height, $width_old, $height_old); return $image_resized; } /** * 获取图片信息 * @param $filename 传过来的参数是文件名字符串 * @return mixed 返回值是一个数组，包含图片宽度、高度、创建和输出的字符串以及扩展名 * @author zsb */ function getImageInfo($filename){ if(@!$info = getimagesize($filename)){//getimagesize()函数可以得到文件信息, //还可以判断图片是否为真实的图片类型，详细功能见PHP手册 exit('文件不是真实图片'); } $fileInfo['width'] = $info[0]; $fileInfo['height'] = $info[1]; $mime = image_type_to_mime_type($info[2]);//info[2]这个是图片类型对应的数字，此函数可以根据该数字返回出文件对应的MIME类型，详细见手册 $createFun = str_replace('/', 'createfrom', $mime);//将$mime中的'/'替换成'createfrom'， //因为后边要用到imagecreatefromjpeg/jpg/png 这个函数，这样就可以动态使用不同的函数了 $outFun = str_replace('/', '', $mime); $fileInfo['createFun'] = $createFun; $fileInfo['outFun'] = $outFun; $fileInfo['ext'] = strtolower(image_type_to_extension($info[2]));//image_type_to_extension()是得到文件后缀名函数 return $fileInfo;//返回文件信息 } /** * 给图片加水印并返回新图片地址 * @param $dstName * @param $srcName * @param int $x 图片水印的位置 (0,0)代表左上角 * @param int $y 图片水印的位置 (0,0)代表左上角 * @param string $dest 默认保存的位置 * @param string $pre 默认文件名前缀 * @param int $pct 图片水印的透明度 * @return string * @author zsb */ function waterImage($dstName, $srcName, $x = 0, $y = 0, $dest = 'images/waterImage', $pre = 'waterImage_', $pct = 100){ //获取图片信息 $dstInfo = getImageInfo($dstName); $srcInfo = getImageInfo($srcName); //创建画布 $dst_im = $dstInfo['createFun']($dstName); $src_im = $srcInfo['createFun']($srcName); $src_width = $srcInfo['width']; $src_height = $srcInfo['height']; $dst_width = $dstInfo['width']; $dst_height = $dstInfo['height']; imagecopymerge($dst_im, $src_im, $x, $y, 0, 0, $src_width, $src_height, $pct); if($dest && !file_exists($dest)){ mkdir($dest,0777,true); } //$randNum = mt_rand(100000,999999); $dstName = "$pre".$dstInfo['ext']; $destination = $dest ? $dest.'/'.$dstName : $dstName; $dstInfo['outFun']($dst_im,$destination); imagedestroy($src_im); imagedestroy($dst_im); return $destination; }

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