2023年7月3日发(作者：)

php添加背景图及设置格式,PHP添加PNG图⽚背景透明⽔印操作类定义与⽤法⽰例本⽂实例讲述了PHP添加PNG图⽚背景透明⽔印操作类定义与⽤法。分享给⼤家供⼤家参考，具体如下：图⽚相关操作类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);$block = imagecreatetruecolor(170,170);//建⽴⼀个画板$bg = imagecolorallocatealpha($block , 0 , 0 , 0 , 127);//拾取⼀个完全透明的颜⾊$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* $bigImgPaths 合成后的图⽚路径 若路径名与第⼀张或第⼆张路径相同 直接覆盖原图*/public function mergerImg($bigImgPath, $smallImgPath, $width, $height, $bigImgPaths){$image_kuang = imagecreatefromstring(file_get_contents($smallImgPath));$image_photo = imagecreatefromstring(file_get_contents($bigImgPath));//创建⼀个新的，和⼤图⼀样⼤的画布$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, $color);/*** 先copy图⽚，再copy画框，实现png的透明效果，将图⽚嵌⼊到画框⾥* imagecopymerge与imagecopy的不同：* imagecopymerge 函数可以⽀持两个图像叠加时，设置叠加层的透明度。imagecopymerge⽐imagecopy多⼀个参数，来设置透明度* PHP内部源码⾥，imagecopymerge在透明度参数为100时，直接调⽤imagecopy函数。* imagecopy 函数则不⽀持叠加透明，但拷贝时可以保留png图像的原透明信息，⽽imagecopymerge却不⽀持图⽚的本⾝的透明拷贝* 即：使⽤imagecopymerge函数，可以实现打上透明度为30%的淡淡的⽔印图标，但图⽚本⾝的png就会变得像IE6不⽀持png透明那样，背景不透明了。* 如果使⽤imagecopy函数，可以保留图⽚本⾝的透明信息，但⽆法实现30%的淡淡⽔印叠加，*/imagecopyresampled($image_3,$image_photo,0,0,0,0,imagesx($image_photo),imagesy($image_photo),imagesx($image_photo)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 $bigImgPaths;}}控制器调⽤⽅法public function test(){$bigImgPath = '';//原图路径$waterImgPath = '';//⽔印图路径$imageTool = new ImageTool($waterImgPath, 'tmp/');//图⽚路径、输出⽂件夹$smallImgPath = $imageTool->rotateImage(45, true)->path;//旋转$width = 0;//⽔印所在X坐标$height = 0;//⽔印所在Y坐标$bigImgPaths = '';//⽣成原图加⽔印新图路径$path = $this->mergerImg($bigImgPath, $smallImgPath, $width, $height, $bigImgPaths);return view('image', compact('path'));}希望本⽂所述对⼤家PHP程序设计有所帮助。