php生成图片缩略图功能示例

  $srcH * $dstW) { $fdstH = round($srcH * $dstW / $srcW); $dstY = floor(($dstH - $fdstH) / 2); $fdstW = $dstW; } else { $fdstW = round($srcW * $dstH / $srcH); $dstX = floor(($dstW - $fdstW) / 2); $fdstH = $dstH; } $ni = ImageCreateTrueColor($dstW, $dstH); $dstX = ($dstX < 0) ? 0 : $dstX; $dstY = ($dstX < 0) ? 0 : $dstY; $dstX = ($dstX > ($dstW / 2)) ? floor($dstW / 2) : $dstX; $dstY = ($dstY > ($dstH / 2)) ? floor($dstH / s) : $dstY; $white = ImageColorAllocate($ni, 255, 255, 255); $black = ImageColorAllocate($ni, 0, 0, 0); imagefilledrectangle($ni, 0, 0, $dstW, $dstH, $white); // 填充背景色 ImageCopyResized($ni, $im, $dstX, $dstY, 0, 0, $fdstW, $fdstH, $srcW, $srcH); if ($markwords != null) { $markwords = iconv("gb2312", "UTF-8", $markwords); //转换文字编码 ImageTTFText($ni, 20, 30, 450, 560, $black, "simhei.ttf", $markwords); //写入文字水印 //参数依次为，文字大小|偏转度|横坐标|纵坐标|文字颜色|文字类型|文字内容 } elseif ($markimage != null) { $wimage_data = GetImageSize($markimage); switch ($wimage_data[2]) { case 1: $wimage = @ImageCreateFromGIF($markimage); break; case 2: $wimage = @ImageCreateFromJPEG($markimage); break; case 3: $wimage = @ImageCreateFromPNG($markimage); break; } imagecopy($ni, $wimage, 500, 560, 0, 0, 88, 31); //写入图片水印,水印图片大小默认为88*31 imagedestroy($wimage); } ImageJpeg($ni, $dstFile, $rate); ImageJpeg($ni, $srcFile, $rate); imagedestroy($im); imagedestroy($ni); } ?>