php 裁剪图片类

<?php
/*
*说明：函数功能是把一个图像裁剪为任意大小的图像，图像不变形
* 参数说明：输入 需要处理图片的 文件名，生成新图片的保存文件名，生成新图片的宽，生成新图片的高
* written by smallchicken
* time 2008-12-18
*/
// 获得任意大小图像，不足地方拉伸，不产生变形，不留下空白
function my_image_resize($src_file, $dst_file , $new_width , $new_height) {
if($new_width <1 || $new_height <1) {
echo "params width or height error !";
exit();
}
if(!file_exists($src_file)) {
echo $src_file . " is not exists !";
exit();
}
// 图像类型
$type=exif_imagetype($src_file);
$support_type=array(IMAGETYPE_JPEG , IMAGETYPE_PNG , IMAGETYPE_GIF);
if(!in_array($type, $support_type,true)) {
echo "this type of image does not support! only support jpg , gif or png";
exit();
}
//Load image
switch($type) {
case IMAGETYPE_JPEG :
$src_img=imagecreatefromjpeg($src_file);
break;
case IMAGETYPE_PNG :
$src_img=imagecreatefrompng($src_file);
break;
case IMAGETYPE_GIF :
$src_img=imagecreatefromgif($src_file);
break;
default:
echo "Load image error!";
exit();
}
$w=imagesx($src_img);
$h=imagesy($src_img);
$ratio_w=1.0 * $new_width / $w;
$ratio_h=1.0 * $new_height / $h;
$ratio=1.0;
// 生成的图像的高宽比原来的都小，或都大 ，原则是 取大比例放大，取大比例缩小（缩小的比例就比较小了）
if( ($ratio_w < 1 && $ratio_h < 1) || ($ratio_w > 1 && $ratio_h > 1)) {
if($ratio_w < $ratio_h) {
$ratio = $ratio_h ; // 情况一，宽度的比例比高度方向的小，按照高度的比例标准来裁剪或放大
}else {
$ratio = $ratio_w ;
}
// 定义一个中间的临时图像，该图像的宽高比 正好满足目标要求
$inter_w=(int)($new_width / $ratio);
$inter_h=(int) ($new_height / $ratio);
$inter_img=imagecreatetruecolor($inter_w , $inter_h);
imagecopy($inter_img, $src_img, 0,0,0,0,$inter_w,$inter_h);
// 生成一个以最大边长度为大小的是目标图像$ratio比例的临时图像
// 定义一个新的图像
$new_img=imagecreatetruecolor($new_width,$new_height);
imagecopyresampled($new_img,$inter_img,0,0,0,0,$new_width,$new_height,$inter_w,$inter_h);
switch($type) {
case IMAGETYPE_JPEG :
imagejpeg($new_img, $dst_file,100); // 存储图像
break;
case IMAGETYPE_PNG :
imagepng($new_img,$dst_file,100);
break;
case IMAGETYPE_GIF :
imagegif($new_img,$dst_file,100);
break;
default:
break;
}
} // end if 1
// 2 目标图像 的一个边大于原图，一个边小于原图 ，先放大平普图像，然后裁剪
// =if( ($ratio_w < 1 && $ratio_h > 1) || ($ratio_w >1 && $ratio_h <1) )
else{
$ratio=$ratio_h>$ratio_w? $ratio_h : $ratio_w; //取比例大的那个值
// 定义一个中间的大图像，该图像的高或宽和目标图像相等，然后对原图放大
$inter_w=(int)($w * $ratio);
$inter_h=(int) ($h * $ratio);
$inter_img=imagecreatetruecolor($inter_w , $inter_h);
//将原图缩放比例后裁剪
imagecopyresampled($inter_img,$src_img,0,0,0,0,$inter_w,$inter_h,$w,$h);
// 定义一个新的图像
$new_img=imagecreatetruecolor($new_width,$new_height);
imagecopy($new_img, $inter_img, 0,0,0,0,$new_width,$new_height);
switch($type) {
case IMAGETYPE_JPEG :
imagejpeg($new_img, $dst_file,100); // 存储图像
break;
case IMAGETYPE_PNG :
imagepng($new_img,$dst_file,100);
break;
case IMAGETYPE_GIF :
imagegif($new_img,$dst_file,100);
break;
default:
break;
}
}// if3
}// end function
?>

第二个方法：

<?php
/*
    图片处理类：缩略，裁剪，圆角，倾斜
*/
class resizeimage
{
   //图片类型
   var $type;
   //实际宽度
   var $width;
   //实际高度
   var $height;
   //改变后的宽度
   var $resize_width;
   //改变后的高度
   var $resize_height;
   //是否裁图
   var $cut;
   //源图象
   var $srcimg;
   //目标图象地址
   var $dstimg;
   //圆角源
   var $corner;
   var $im;

function resizeimage($img, $corner, $wid, $hei,$c, $corner_radius, $angle)
   {
       $this->srcimg = $img;
       $this->corner = $corner;
       $this->resize_width = $wid;
       $this->resize_height = $hei;
       $this->cut = $c;
       $this->corner_radius = $corner_radius;
       $this->angle = $angle;
       //图片的类型
       $this->type = substr(strrchr($this->srcimg,"."),1);
       //初始化图象
       $this->initi_img();
       //目标图象地址
       $this -> dst_img();
       //--
       $this->width = imagesx($this->im);
       $this->height = imagesy($this->im);
       //生成图象
       $this->newimg();
       ImageDestroy ($this->im);
   }
   function newimg()
   {
       //改变后的图象的比例
       $resize_ratio = ($this->resize_width)/($this->resize_height);
       //实际图象的比例
       $ratio = ($this->width)/($this->height);
       if(($this->cut)=="1")
       //裁图
       {
           if($ratio>=$resize_ratio)
           //高度优先
           {
               $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width,$this->resize_height, (($this->height)*$resize_ratio), $this->height);
               $tmp = $this->rounded_corner($newimg,$this->resize_width);
               imagepng ($tmp,$this->dstimg);
           }
           if($ratio<$resize_ratio)
           //宽度优先
           {
               $newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, $this->resize_height, $this->width, (($this->width)/$resize_ratio));
               $tmp = $this->rounded_corner($newimg);
               imagepng ($tmp,$this->dstimg);
           }
       }
       else
       //不裁图
       {
           if($ratio>=$resize_ratio)
           {
               $newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, $this->resize_width, ($this->resize_width)/$ratio, $this->width, $this->height);
               ImageJpeg ($newimg,$this->dstimg);
           }
           if($ratio<$resize_ratio)
           {
               $newimg = imagecreatetruecolor(($this->resize_height)*$ratio,$this->resize_height);
               imagecopyresampled($newimg, $this->im, 0, 0, 0, 0, ($this->resize_height)*$ratio, $this->resize_height, $this->width, $this->height);
               ImageJpeg ($newimg,$this->dstimg);
           }
       }
   }
   //初始化图象
   function initi_img()
   {
       if($this->type=="jpg")
       {
           $this->im = imagecreatefromjpeg($this->srcimg);
       }
       if($this->type=="gif")
       {
           $this->im = imagecreatefromgif($this->srcimg);
       }
       if($this->type=="png")
       {
           $this->im = imagecreatefrompng($this->srcimg);
       }
   }

   //处理圆角
   function rounded_corner($image,$size)
   {
        $this->angle = 0;
        $topleft = true;
        $bottomleft = true;
        $bottomright = true;
        $topright = true;
        $corner_source = imagecreatefrompng('rounded_corner.png');
        $corner_width = imagesx($corner_source);
        $corner_height = imagesy($corner_source);
        $corner_resized = ImageCreateTrueColor($this->corner_radius, $this->corner_radius);
        ImageCopyResampled($corner_resized, $corner_source, 0, 0, 0, 0, $this->corner_radius, $this->corner_radius, $corner_width, $corner_height);
        $corner_width = imagesx($corner_resized);
        $corner_height = imagesy($corner_resized);
        $white = ImageColorAllocate($image,255,255,255);
        $black = ImageColorAllocate($image,0,0,0);

        //顶部左圆角
        if ($topleft == true) {
            $dest_x = 0;
            $dest_y = 0;
            imagecolortransparent($corner_resized, $black);
            imagecopymerge($image, $corner_resized, $dest_x, $dest_y, 0, 0, $corner_width, $corner_height, 100);
        } 

        //下部左圆角
        if ($bottomleft == true) {
            $dest_x = 0;
            $dest_y = $size - $corner_height;
            $rotated = imagerotate($corner_resized, 90, 0);
            imagecolortransparent($rotated, $black);
            imagecopymerge($image, $rotated, $dest_x, $dest_y, 0, 0, $corner_width, $corner_height, 100);
        }

        //下部右圆角
        if ($bottomright == true) {
            $dest_x = $size - $corner_width;
            $dest_y = $size - $corner_height;
            $rotated = imagerotate($corner_resized, 180, 0);
            imagecolortransparent($rotated, $black);
            imagecopymerge($image, $rotated, $dest_x, $dest_y, 0, 0, $corner_width, $corner_height, 100);
        }

        //顶部右圆角
        if ($topright == true) {
            $dest_x = $size - $corner_width;
            $dest_y = 0;
            $rotated = imagerotate($corner_resized, 270, 0);
            imagecolortransparent($rotated, $black);
            imagecopymerge($image, $rotated, $dest_x, $dest_y, 0, 0, $corner_width, $corner_height, 100);
        }
        $image = imagerotate($image, $this->angle, $white);
        return $image;
   }

   //图象目标地址
   function dst_img()
   {
       $full_length = strlen($this->srcimg);
       $type_length = strlen($this->type);
       $name_length = $full_length-$type_length;
       $name         = substr($this->srcimg,0,$name_length-1);
       $this->dstimg = $name."_small.png";
   }
}

//resizeimage("图片地址", "处理后的宽度", "处理后的高度", "是否裁剪", "圆角度数", "倾斜度");
$img_file = 'Sunset.jpg';
$corner = 'rounded_corner.png';
$resizeimage = new resizeimage($img_file, $corner, "80", "80", "1", "6", "0");
?>
<img src="Sunset_small.png" border="0">