本文实例讲述了PHP实现图片不变型裁剪及图片按比例裁剪的方法。分享给大家供大家参考，具体如下：

图片不变型裁剪

<?php/** * imageCropper * @param string $source_path * @param string $target_width * @param string $target_height */function imageCropper($source_path, $target_width, $target_height){ $source_info = getimagesize($source_path); $source_width = $source_info[0]; $source_height = $source_info[1]; $source_mime = $source_info['mime']; $source_ratio = $source_height / $source_width; $target_ratio = $target_height / $target_width; if ($source_ratio > $target_ratio){ // image-to-height $cropped_width = $source_width; $cropped_height = $source_width * $target_ratio; $source_x = 0; $source_y = ($source_height - $cropped_height) / 2; }elseif ($source_ratio < $target_ratio){ //image-to-widht $cropped_width = $source_height / $target_ratio; $cropped_height = $source_height; $source_x = ($source_width - $cropped_width) / 2; $source_y = 0; }else{ //image-size-ok $cropped_width = $source_width; $cropped_height = $source_height; $source_x = 0; $source_y = 0; } switch ($source_mime){ case 'image/gif': $source_image = imagecreatefromgif($source_path); break; case 'image/jpeg': $source_image = imagecreatefromjpeg($source_path); break; case 'image/png': $source_image = imagecreatefrompng($source_path); break; default: return ; break; } $target_image = imagecreatetruecolor($target_width, $target_height); $cropped_image = imagecreatetruecolor($cropped_width, $cropped_height); // copy imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height); // zoom imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height); header('Content-Type: image/jpeg'); imagejpeg($target_image); imagedestroy($source_image); imagedestroy($target_image); imagedestroy($cropped_image);}$filename = "8fcb7a0831b79c61.jpg";imageCropper($filename,200,200);?>

图片按比例裁剪

<?php/** * imageZoom * @param string $file * @param double $zoom */function imageZoom($filename,$zoom=0.6){ //baseinfo $sourceImageInfo = getimagesize($filename); $sourceWidth = $sourceImageInfo[0]; $sourceHeight = $sourceImageInfo[1]; $sourceMine = $sourceImageInfo['mime']; $sourceRatio = $sourceWidth/$sourceHeight; $sourceX = 0; $sourceY = 0; //zoom $targetRatio = $zoom; //target-widht-height $targetWidth = $sourceWidth*$targetRatio; $targetHeight = $sourceHeight*$targetRatio; //init-params $sourceImage = null; switch($sourceMine){ case 'image/gif': $sourceImage = imagecreatefromgif($filename); break; case 'image/jpeg': $sourceImage = imagecreatefromjpeg($filename); break; case 'image/png': $sourceImage = imagecreatefrompng($filename); break; default: return ; break; } //temp-target-image $tempSourceImage = imagecreatetruecolor($sourceWidth, $sourceHeight); $targetImage = imagecreatetruecolor($targetWidth,$targetHeight); //copy imagecopy($tempSourceImage, $sourceImage, 0, 0, $sourceX, $sourceY, $sourceWidth, $sourceHeight); //zoom imagecopyresampled($targetImage, $tempSourceImage, 0, 0, 0, 0, $targetWidth, $targetHeight, $sourceWidth, $sourceHeight); //header header('Content-Type: image/jpeg'); //image-loading imagejpeg($targetImage); //destroy imagedestroy($tempSourceImage); imagedestroy($sourceImage); imagedestroy($targetImage);}$filename = "8fcb7a0831b79c61.jpg";imageZoom($filename);?>

希望本文所述对大家PHP程序设计有所帮助。