处理原有的图像
图片处理，缩放，裁剪，翻转，旋转，透明，锐化等图片操作
一.创建图片资源
imagecreatetruecolor(width,height);
gif jpg png
imagecreatefromgif(图片名称);
imagecreatefrompng(图片名称);
imagecreatefromjpeg(图片名称);
画出各种图形（圆形、矩形、线段、文字）
imagegif(图片位置);
imagepng(图片位置);
imagejpeg(图片位置);
imagedestroy(图片资源);
<?php //利用原有的图片创建图片资源 $img=imagecreatefromgif("./images/map.gif"); //设置颜色 $red=imagecolorallocate($img, 255, 0, 0); //画线 imageline($img,0, 0, 100, 100, $red); //画圆 imageellipse($img, 200, 100, 100, 100, $red); //保存图片 imagegif($img,"./images/map2.gif"); //释放资源 imagedestroy($img); ?>
二.获取图片的属性
imagesx(res); 取得图片的宽度
imagesy(res); 取得图片的高度
getimagesize(图片名称); 返回数组，0==width,1==height,2==type
<?php $img=imagecreatefromgif("./images/map.gif"); $red=imagecolorallocate($img, 255, 0, 0); //输出图片的高度和宽度 echo ''.imagesx($img)."<br>"; echo 'height:'.imagesy($img)."<br>"; echo '<pre>'; //取得图像大小 print_r(getimagesize("./images/map.gif")); echo '</pre>'; imagedestroy($img); ?>
三.透明处理
png jpeg 透明都正常，只有gif不正常
imagecolortransparent(); 将某个颜色定义为透明色
imagecolorstotal(); 取得一幅图像的调色板中颜色的数目
imagecolorsforindex(); 取得某索引的颜色
<?php function thumn($background,$newWidth,$newHeight,$newFile){ //取出图片的宽高 list($width,$height)=getimagesize($background); //求的而缩放的宽高 if ($newWidth && ($width < $height)){ $newWidth=($newHeight/$height)*$width; } else { $newHeight=($newWidth/$width)*$height; } //创建缩放后图片的画布 $new=imagecreatetruecolor($newWidth,$newHeight); $img=imagecreatefromgif($background); //imagecolortransparent(); 将某个颜色定义为透明色 $otsc=imagecolortransparent($img); //imagecolorstotal(); 取得一幅图像的调色板中颜色的数目 if($otsc>=0 && $otsc<imagecolorstotal($img)){ //imagecolorsforindex(); 取得某索引的颜色 $tran=imagecolorsforindex($img, $otsc); //新的颜色 $newt=imagecolorallocate($new, $tran["red"], $tran["green"], $tran["blue"]); //新的颜色设为缩放图片的颜色 imagefill($new, 0, 0, $newt); //将缩放图片的颜色设为背景透明 imagecolortransparent($new,newt); } //缩放原图片 imagecopyresampled($new, $img,0,0,0,0, $newWidth, $newHeight, $width, $height); //保存缩放后的图片 imagegif($new,$newFile); //释放资源 imagedestroy($new); imagedestroy($img); } thumn("images/map.gif",200,200,"./images/map3.gif"); ?>
四.图片的裁剪
imagecopyresized(); 拷贝部分图像并调整大小
imagecopyresampled(); 重采样拷贝部分图像并调整大小
<?php function cut($background, $cut_x, $cut_y, $cut_width, $cut_height, $location){ $back=imagecreatefromjpeg($background); $new=imagecreatetruecolor($cut_width, $cut_height); imagecopyresampled($new, $back, 0, 0, $cut_x, $cut_y, $cut_width, $cut_height,$cut_width,$cut_height); imagejpeg($new, $location); imagedestroy($new); imagedestroy($back); } cut("./images/hee.jpg", 440, 140, 117, 112, "./images/hee5.jpg"); ?>
五、加水印（文字， 图片）
imagettftext();
imagecopy();
<?php function mark_text($background, $text, $x, $y){ $back=imagecreatefromjpeg($background); $color=imagecolorallocate($back, 0, 255, 0); imagettftext($back, 20, 0, $x, $y, $color, "simkai.ttf", $text); imagejpeg($back, "./images/hee7.jpg"); imagedestroy($back); } mark_text("./images/hee.jpg", "细说PHP", 150, 250); function mark_pic($background, $waterpic, $x, $y){ $back=imagecreatefromjpeg($background); $water=imagecreatefromgif($waterpic); $w_w=imagesx($water); $w_h=imagesy($water); imagecopy($back, $water, $x, $y, 0, 0, $w_w, $w_h); imagejpeg($back,"./images/hee8.jpg"); imagedestroy($back); imagedestroy($water); } mark_pic("./images/hee.jpg", "./images/gaolf.gif", 50, 200) ?>
六、图片旋转
imagerotate -- 用给定角度旋转图像
<?php $back=imagecreatefromjpeg("./images/hee.jpg"); $new=imagerotate($back, 45, 0); imagejpeg($new, "./images/hee9.jpg"); ?>
七、图片翻转
沿Y轴
沿X轴
<?php function turn_y($background, $newfile){ $back=imagecreatefromjpeg($background); $width=imagesx($back); $height=imagesy($back); $new=imagecreatetruecolor($width, $height); for($x=0; $x < $width; $x++){ imagecopy($new, $back, $width-$x-1, 0, $x, 0, 1, $height); } imagejpeg($new, $newfile); imagedestroy($back); imagedestroy($new); } function turn_x($background, $newfile){ $back=imagecreatefromjpeg($background); $width=imagesx($back); $height=imagesy($back); $new=imagecreatetruecolor($width, $height); for($y=0; $y < $height; $y++){ imagecopy($new, $back,0, $height-$y-1, 0, $y, $width, 1); } imagejpeg($new, $newfile); imagedestroy($back); imagedestroy($new); } turn_y("./images/hee.jpg", "./images/hee11.jpg"); turn_x("./images/hee.jpg", "./images/hee12.jpg"); ?>
八、锐化
imagecolorsforindex()
imagecolorat()
<?php function sharp($background, $degree, $save){ $back=imagecreatefromjpeg($background); $b_x=imagesx($back); $b_y=imagesy($back); $dst=imagecreatefromjpeg($background); for($i=0; $i<$b_x; $i++){ for($j=0; $j<$b_y; $j++){ $b_clr1=imagecolorsforindex($back, imagecolorat($back, $i-1, $j-1)); $b_clr2=imagecolorsforindex($back, imagecolorat($back, $i, $j)); $r=intval($b_clr2["red"]+$degree*($b_clr2["red"]-$b_clr1["red"])); $g=intval($b_clr2["green"]+$degree*($b_clr2["green"]-$b_clr1["green"])); $b=intval($b_clr2["blue"]+$degree*($b_clr2["blue"]-$b_clr1["blue"])); $r=min(255, max($r, 0)); $g=min(255, max($g, 0)); $b=min(255, max($b, 0)); if(($d_clr=imagecolorexact($dst, $r, $g, $b))==-1){ $d_clr=Imagecolorallocate($dst, $r, $g, $b); } imagesetpixel($dst, $i, $j, $d_clr); } } imagejpeg($dst, $save); imagedestroy($back); imagedestroy($dst); } sharp("./images/hee.jpg", 20, "./images/hee13.jpg"); ?>