PHP如何实现图片处理_PHP图片处理功能的实现方法与代码实例

<strong><?php<br>// 原图路径<br>$source = 'original.jpg';<br>// 获取原图信息<brlist($width, $height) = getimagesize($source);<br>// 设置缩略图最大宽高<br>$max_width = 200;<br>$max_height = 200;<br>// 计算缩放比例<br>$ratio = min($max_width / $width, $max_height / $height);<br>$new_width = (int)($width * $ratio);<br>$new_height = (int)($height * $ratio);<br>// 创建新图像资源<br>$thumb = imagecreatetruecolor($new_width, $new_height);<br>// 根据格式加载原图<br>$image = imagecreatefromjpeg($source);<br>// 缩放复制<br>imagecopyresampled($thumb, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);<br>// 输出到文件<br>imagejpeg($thumb, 'thumb.jpg', 80); // 质量 80%<br>// 释放内存<br>imagedestroy($thumb);<br>imagedestroy($image);<br>?></strong>

<strong><?php<br>$img = 'photo.jpg';<br>$image = imagecreatefromjpeg($img);<br>$width = imagesx($image);<br>$height = imagesy($image);<br>// 水印文字<br>$text = '© MySite';<br>$font_size = 16;<br>$font_color = imagecolorallocate($image, 255, 255, 255); // 白色<br>// 计算文字位置<br>$bbox = imagettfbbox($font_size, 0, 'arial.ttf', $text);<br>$text_width = $bbox[2] - $bbox[0];<br>$text_height = $bbox[7] - $bbox[1];<br>$x = $width - $text_width - 10;<br>$y = $height - $text_height - 10;<br>// 添加文字<br>imagettftext($image, $font_size, 0, $x, $y, $font_color, 'arial.ttf', $text);<br>// 保存结果<br>imagejpeg($image, 'watermarked.jpg');<br>imagedestroy($image);<br>?></strong>

<strong><?php<br>$jpg_image = imagecreatefromjpeg('input.jpg');<br>imagepng($jpg_image, 'output.png');<br>imagedestroy($jpg_image);<br>?></strong>

<strong><?php<br>$src = 'photo.jpg';<br>$image = imagecreatefromjpeg($src);<br>// 裁剪参数：x, y, 宽, 高<br>$crop_x = 50;<br>$crop_y = 50;<br>$crop_width = 200;<br>$crop_height = 200;<br>$cropped = imagecreatetruecolor($crop_width, $crop_height);<br>imagecopy($cropped, $image, 0, 0, $crop_x, $crop_y, $crop_width, $crop_height);<br>imagejpeg($cropped, 'cropped.jpg');<br>imagedestroy($image);<br>imagedestroy($cropped);<br>?></strong>