我正在使用以下类压缩图像..
<?PHP class SimpleImage { var $image; var $image_type; function load($filename) { $image_info = getimagesize($filename); $this->image_type = $image_info[2]; if( $this->image_type == IMAGETYPE_JPEG ) { $this->image = imagecreatefromjpeg($filename); } elseif( $this->image_type == IMAGETYPE_GIF ) { $this->image = imagecreatefromgif($filename); } elseif( $this->image_type == IMAGETYPE_PNG ) { $this->image = imagecreatefrompng($filename); } } function save($filename,$image_type=IMAGETYPE_JPEG,$compression=75,$permissions=null){ if( $image_type == IMAGETYPE_JPEG ) { imagejpeg($this->image,$filename,$compression); } elseif( $image_type == IMAGETYPE_GIF ) { imagegif($this->image,$filename); } elseif( $image_type == IMAGETYPE_PNG ) { imagepng($this->image,$filename); } if( $permissions != null) { chmod($filename,$permissions); } } function output($image_type=IMAGETYPE_JPEG) { if( $image_type == IMAGETYPE_JPEG ) { imagejpeg($this->image); } elseif( $image_type == IMAGETYPE_GIF ) { imagegif($this->image); } elseif( $image_type == IMAGETYPE_PNG ) { imagepng($this->image); } } function getWidth() { return imagesx($this->image); } function getHeight() { return imagesy($this->image); } function resizetoHeight($height) { $ratio = $height / $this->getHeight(); $width = $this->getWidth() * $ratio; $this->resize($width,$height); } function resizetoWidth($width) { $ratio = $width / $this->getWidth(); $height = $this->getheight() * $ratio; $this->resize($width,$height); } function scale($scale) { $width = $this->getWidth() * $scale/100; $height = $this->getheight() * $scale/100; $this->resize($width,$height); } function resize($width,$height) { $new_image = imagecreatetruecolor($width,$height); imagecopyresampled($new_image,$this->image,$width,$height,$this->getWidth(),$this->getHeight()); $this->image = $new_image; } } ?>
include_once(ROOT.'/library/SimpleImage.PHP') $image = new SimpleImage(); $image->load($image_name); $image->resizetoWidth(100); $image->save($image_name);
现在的问题是我的图像被压缩了,但它们的原始颜色组合丢失了……
不知道该怎么办.. ??
请建议另一个类进行图像压缩.
解决方法
这是我很久以前编写的一个函数,它不是真正优化的,但它应该可以解决问题.适用于各种mime类型,并允许您将修改后的图像保存到新位置.如果您需要更少的功能,可以轻松简化它.
public function resizePicture($path,$new_path,$new_width,$new_height,$proportion = false) { $size = getimagesize($path); $x = 0; $y = 0; switch($size['mime']) { case 'image/jpeg': $picture = imagecreatefromjpeg($path); break; case 'image/png': $picture = imagecreatefrompng($path); break; case 'image/gif': $picture = imagecreatefromgif($path); break; default: return false; break; } $width = $size[0]; $height = $size[1]; $frame = imagecreatetruecolor($new_width,$new_height); if($size['mime'] == 'image/jpeg') { $bg = imagecolorallocate($frame,255,255); imagefill($frame,$bg); } else if($size['mime'] == 'image/gif' or $size['mime'] == 'image/png') { imagealphablending($picture,false); imagesavealpha($picture,true); imagealphablending($frame,false); imagesavealpha($frame,true); } if($width < $new_width and $height < $new_height) { $x = ($new_width - $width) / 2; $y = ($new_height - $height) / 2; imagecopy($frame,$picture,$x,$y,$height); } else { if($proportion and $width != $height) { if($width > $height) { $old_height = $new_height; $new_height = $height * $new_width / $width; $y = abs($old_height - $new_height) / 2; } else { $old_width = $new_width; $new_width = $width * $new_height / $height; $x = abs($old_width - $new_width) / 2; } } imagecopyresampled($frame,$height); } switch($size['mime']) { case 'image/jpeg': imagejpeg($frame,85); break; case 'image/png': imagepng($frame,8); break; case 'image/gif': imagegif($frame,$new_path); break; default: return false; break; } }