相信很多人都想过如何用PHP生成GIF动画来实现动态图片验证码,以下是实现过程。
ImageCode函数通过GIFEncoder类实现的GIF动画的PHP源代码,有兴趣的朋友可以研究一下。
效果如图:
- /**
- * ImageCode 生成GIF图片验证
- * @param $string 字符串
- * @param $width 宽度
- * @param $height 高度
- * */
- function ImageCode($string = '', $width = 75, $height = 25)
- {
- $authstr = $string ? $string : ((time() % 2 == 0) ? mt_rand(1000, 9999) : mt_rand(10000, 99999));
- $board_width = $width;
- $board_height = $height;
- // 生成一个32帧的GIF动画
- for($i = 0; $i < 32; $i++)
- {
- ob_start();
- $image = imagecreate($board_width, $board_height);
- imagecolorallocate($image, 0,0,0);
- // 设定文字颜色数组
- $colorList[] = ImageColorAllocate($image, 15,73,210);
- $colorList[] = ImageColorAllocate($image, 0,64,0);
- $colorList[] = ImageColorAllocate($image, 0,0,64);
- $colorList[] = ImageColorAllocate($image, 0,128,128);
- $colorList[] = ImageColorAllocate($image, 27,52,47);
- $colorList[] = ImageColorAllocate($image, 51,0,102);
- $colorList[] = ImageColorAllocate($image, 0,0,145);
- $colorList[] = ImageColorAllocate($image, 0,0,113);
- $colorList[] = ImageColorAllocate($image, 0,51,51);
- $colorList[] = ImageColorAllocate($image, 158,180,35);
- $colorList[] = ImageColorAllocate($image, 59,59,59);
- $colorList[] = ImageColorAllocate($image, 0,0,0);
- $colorList[] = ImageColorAllocate($image, 1,128,180);
- $colorList[] = ImageColorAllocate($image, 0,153,51);
- $colorList[] = ImageColorAllocate($image, 60,131,1);
- $colorList[] = ImageColorAllocate($image, 0,0,0);
- $fontcolor = ImageColorAllocate($image, 0,0,0);
- $gray = ImageColorAllocate($image, 245,245,245);
- $color = imagecolorallocate($image, 255,255,255);
- $color2 = imagecolorallocate($image, 255,0,0);
- imagefill($image, 0, 0, $gray);
- $space = 15; // 字符间距
- if($i > 0) // 屏蔽***帧
- {
- for ($k = 0; $k < strlen($authstr); $k++)
- {
- $colorRandom = mt_rand(0,sizeof($colorList)-1);
- $float_top = rand(0,4);
- $float_left = rand(0,3);
- imagestring($image, 6, $space * $k, $top + $float_top, substr($authstr, $k, 1), $colorList[$colorRandom]);
- }
- }
- for ($k = 0; $k < 20; $k++)
- {
- $colorRandom = mt_rand(0,sizeof($colorList)-1);
- imagesetpixel($image, rand()%70 , rand()%15 , $colorList[$colorRandom]);
- }
- // 添加干扰线
- for($k = 0; $k < 3; $k++)
- {
- $colorRandom = mt_rand(0, sizeof($colorList)-1);
- // $todrawline = rand(0,1);
- $todrawline = 1;
- if($todrawline)
- {
- imageline($image, mt_rand(0, $board_width), mt_rand(0,$board_height), mt_rand(0,$board_width), mt_rand(0,$board_height), $colorList[$colorRandom]);
- }
- else
- {
- $w = mt_rand(0,$board_width);
- $h = mt_rand(0,$board_width);
- imagearc($image, $board_width - floor($w / 2) , floor($h / 2), $w, $h, rand(90,180), rand(180,270), $colorList[$colorRandom]);
- }
- }
- imagegif($image);
- imagedestroy($image);
- $imagedata[] = ob_get_contents();
- ob_clean();
- ++$i;
- }
- $gif = new GIFEncoder($imagedata);
- Header ('Content-type:image/gif');
- echo $gif->GetAnimation();
- }
有关GIFEncoder类,请下载本文附件:animation.ra
附件下载:animation.rar 2.96KB