PHP Add PNG Image Background Transparent Watermark Operation Class Definition and Usage Example
- 2021-11-29 23:20:50
- OfStack
This paper describes the definition and usage of PHP adding PNG picture background transparent watermark operation class. Share it for your reference, as follows:
Picture related operation class
class ImageTool
{
private $imagePath;//图片路径
private $outputDir;//输出文件夹
public $memoryImg;//内存图像
public $path;
public function __construct($imagePath, $outputDir = null)
{
$this->imagePath = $imagePath;
$this->outputDir = $outputDir;
$this->memoryImg = null;
$this->path = null;
}
/**
* 显示内存中的图片
* @param $image
*/
public function showImage()
{
if ($this->memoryImg != null) {
$info = getimagesize($this->imagePath);
$type = image_type_to_extension($info[2], false);
header('Content-type:' . $info['mime']);
$funs = "image{$type}";
$funs($this->memoryImg);
imagedestroy($this->memoryImg);
$this->memoryImg = null;
}
}
/**
* 保存图片
* @param $image 图片路径
* @return string
*/
private function saveImage($image)
{
$info = getimagesize($this->imagePath);
$type = image_type_to_extension($info[2], false);
$funs = "image{$type}";
if (empty($this->outputDir)) {
$funs($image, md5($this->imagePath) . '.' . $type);
return md5($this->imagePath) . '.' . $type;
} else {
$funs($image, $this->outputDir . md5($this->imagePath) . '.' . $type);
return $this->outputDir . md5($this->imagePath) . '.' . $type;
}
}
/**
* 压缩图片
* @param $width 压缩后宽度
* @param $height 压缩后高度
* @param bool $output 是否输出文件
* @return resource
*/
public function compressImage($width, $height, $output = false)
{
$image = null;
$info = getimagesize($this->imagePath);
$type = image_type_to_extension($info[2], false);
$fun = "imagecreatefrom{$type}";
$image = $fun($this->imagePath);
imagesavealpha($image,true);//
$thumbnail = imagecreatetruecolor($width, $height);
imagealphablending($thumbnail,false);//这里很重要,意思是不合并颜色,直接用$img图像颜色替换,包括透明色;
imagesavealpha($thumbnail,true);//
imagecopyresampled($thumbnail, $image, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
imagedestroy($image);
if ($output) {
$path = $this->saveImage($thumbnail);
$this->path = $path;
}
$this->memoryImg = $thumbnail;
return $this;
}
/**
* 为图像添加文字标记
*
* @param $content 文本内容
* @param $size 字体大小
* @param $font 字体样式
* @param bool $output 是否输出文件
* @return $this
*/
public function addTextmark($content, $size, $font, $output = false)
{
$info = getimagesize($this->imagePath);
$type = image_type_to_extension($info[2], false);
$fun = "imagecreatefrom{$type}";
$image = $fun($this->imagePath);
$color = imagecolorallocatealpha($image, 0, 0, 0, 80);
$posX = imagesx($image) - strlen($content) * $size / 2;
$posY = imagesy($image) - $size / 1.5;
imagettftext($image, $size, 0, $posX, $posY, $color, $font, $content);
if ($output) {
$this->saveImage($image);
}
$this->memoryImg = $image;
return $this;
}
/**
* 为图片添加水印
*
* @param $watermark 水印图片路径
* @param $alpha 水印透明度(0-100)
* @param bool $output 是否输出文件
* @return $this
*/
public function addWatermark($watermark, $alpha, $output = false)
{
$image_info = getimagesize($this->imagePath);
$image_type = image_type_to_extension($image_info[2], false);
$image_fun = "imagecreatefrom{$image_type}";
$image = $image_fun($this->imagePath);
$mark_info = getimagesize($watermark);
$mark_type = image_type_to_extension($mark_info[2], false);
$mark_fun = "imagecreatefrom{$mark_type}";
$mark = $mark_fun($watermark);
$posX = imagesx($image) - imagesx($mark);
$posY = imagesy($image) - imagesy($mark);
imagesavealpha($mark, true);
imagecopymerge($image, $mark, $posX, $posY, 0, 0, $mark_info[0], $mark_info[1], $alpha);
imagesavealpha($mark, true);
if ($output) {
$path = $this->saveImage($image);
$this->path = $path;
}
$this->memoryImg = $image;
return $this;
}
//用给定角度旋转图像，以jpeg图像格式为例
/**
* 水印图片旋转
* @param $degrees 旋转角度
* @param bool $output 是否保存图片
* @return $this
*/
function rotateImage($degrees, $output = false)
{
$info = getimagesize($this->imagePath);
$type = image_type_to_extension($info[2], false);
$fun = "imagecreatefrom{$type}";
$image = $fun($this->imagePath);
$block = imagecreatetruecolor(170,170);//建立1个画板
$bg = imagecolorallocatealpha($block , 0 , 0 , 0 , 127);//拾取1个完全透明的颜色
$image = imagerotate($image, $degrees, $bg ,0);
imagesavealpha($image, true);
header("Content-type: image/{$type}");
//旋转后的图片保存
if ($output) {
$path = $this->saveImage($image);
$this->path = $path;
}
$this->memoryImg = $image;
return $this;
}
/**
* 添加PNG透明图片
* $bigImgPath 目标图片路径
* $smallImgPath 水印图片路径
* $width 相对于目标图的x轴放置位置 左上角为 0
* $height 相对于目标图的y轴放置位置 左上角为0
* $bigImgPaths 合成后的图片路径 若路径名与第1张或第2张路径相同 直接覆盖原图
*/
public function mergerImg($bigImgPath, $smallImgPath, $width, $height, $bigImgPaths)
{
$image_kuang = imagecreatefromstring(file_get_contents($smallImgPath));
$image_photo = imagecreatefromstring(file_get_contents($bigImgPath));
//创建1个新的，和大图1样大的画布
$image_3 = imageCreatetruecolor(imagesx($image_photo), imagesy($image_photo));
//为真彩色画布创建白色背景，再设置为透明
$color = imagecolorallocate($image_3, 255, 255, 255);
imagefill($image_3, 0, 0, $color);
imageColorTransparent($image_3, $color);
/**
* 先copy图片，再copy画框，实现png的透明效果，将图片嵌入到画框里
* imagecopymerge与imagecopy的不同：
* imagecopymerge 函数可以支持两个图像叠加时，设置叠加层的透明度。imagecopymerge比imagecopy多1个参数，来设置透明度
* PHP内部源码里，imagecopymerge在透明度参数为100时，直接调用imagecopy函数。
* imagecopy 函数则不支持叠加透明，但拷贝时可以保留png图像的原透明信息，而imagecopymerge却不支持图片的本身的透明拷贝
* 即：使用imagecopymerge函数，可以实现打上透明度为30%的淡淡的水印图标，但图片本身的png就会变得像IE6不支持png透明那样，背景不透明了。
* 如果使用imagecopy函数，可以保留图片本身的透明信息，但无法实现30%的淡淡水印叠加，
*/
imagecopyresampled($image_3,$image_photo,0,0,0,0,imagesx($image_photo),imagesy($image_photo),imagesx($image_photo),imagesy($image_photo));
imagecopy($image_3,$image_kuang, $width,$height,0,0,imagesx($image_kuang),imagesy($image_kuang));
//存储图片路径
imagejpeg($image_3, $bigImgPaths);
return $bigImgPaths;
}
}
Controller call method
public function test()
{
$bigImgPath = 'ren.jpg';// Original path
$waterImgPath = 'tae.png';// Watermark path
$imageTool = new ImageTool($waterImgPath, 'tmp/');// Picture path, output folder
$smallImgPath = $imageTool->rotateImage(45, true)->path;// Rotate
$width = 0;// Where the watermark is located X Coordinates
$height = 0;// Where the watermark is located Y Coordinates
$bigImgPaths = 'new.png';// Generate the original image and watermark the new image path
$path = $this->mergerImg($bigImgPath, $smallImgPath, $width, $height, $bigImgPaths);
return view('image', compact('path'));
}
For more readers interested in PHP related contents, please check the special topics of this site: "Summary of PHP Graphics and Pictures Operation Skills", "PHP Array (Array) Operation Skills", "PHP Data Structure and Algorithm Tutorial", "php Programming Algorithm Summary", "PHP Mathematical Operation Skills Summary", "php String (string) Usage Summary" and "php Common Database Operation Skills Summary"
I hope this article is helpful to everyone's PHP programming.