php转换bmp图片格式为jpg格式
Posted 北风吹秋风凉
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进行图片格式转换前,先输出phpinfo()查看php库信息,查看gd扩展库是否开启,若未开启,打开php.ini文件,用查找工具找到extension=php_gd2.dll,把extension=php_gd2.dll 前面的【;】,就可以了
这里转换成为jpg格式需要JPEG Support支持,png需要 PNG Support支持,对应的先检查自己转的格式是否支持
imagejpeg()函数失败也许是你的文件夹权限问题,得多注意
可以先用function_exist()函数ImageCreateFromBMP检查是否存在,下例中的ImageCreateFromBMP_private用来代替ImageCreateFromBMP方法
示例代码如下:
<?php $srcFile =\'test.bmp\';//需要转换的图片 $info = getimagesize($srcFile); $srcFileExt=$info[\'mime\']; //判断是否是bmp格式 if($srcFileExt==\'image/x-ms-bmp\'){ $result = changeBMPtoJPG($srcFile); if($result){ echo $result; }else{ echo "转换失败!"; } }else{ echo "该图片不是bmp格式"; } exit; function ImageCreateFromBMP_private($filename) { if (!$f1 = fopen($filename, "rb")) return false; $FILE = unpack("vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread($f1, 14)); if ($FILE[\'file_type\'] != 19778) return false; $BMP = unpack(\'Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel\' . \'/Vcompression/Vsize_bitmap/Vhoriz_resolution\' . \'/Vvert_resolution/Vcolors_used/Vcolors_important\', fread($f1, 40)); $BMP[\'colors\'] = pow(2, $BMP[\'bits_per_pixel\']); if ($BMP[\'size_bitmap\'] == 0) $BMP[\'size_bitmap\'] = $FILE[\'file_size\'] - $FILE[\'bitmap_offset\']; $BMP[\'bytes_per_pixel\'] = $BMP[\'bits_per_pixel\'] / 8; $BMP[\'bytes_per_pixel2\'] = ceil($BMP[\'bytes_per_pixel\']); $BMP[\'decal\'] = ($BMP[\'width\'] * $BMP[\'bytes_per_pixel\'] / 4); $BMP[\'decal\'] -= floor($BMP[\'width\'] * $BMP[\'bytes_per_pixel\'] / 4); $BMP[\'decal\'] = 4 - (4 * $BMP[\'decal\']); if ($BMP[\'decal\'] == 4) $BMP[\'decal\'] = 0; $PALETTE = array(); if ($BMP[\'colors\'] < 16777216) { $PALETTE = unpack(\'V\' . $BMP[\'colors\'], fread($f1, $BMP[\'colors\'] * 4)); } $IMG = fread($f1, $BMP[\'size_bitmap\']); $VIDE = chr(0); $res = imagecreatetruecolor($BMP[\'width\'], $BMP[\'height\']); $P = 0; $Y = $BMP[\'height\'] - 1; while ($Y >= 0) { $X = 0; while ($X < $BMP[\'width\']) { switch ($BMP[\'bits_per_pixel\']) { case 32: $COLOR = unpack("V", substr($IMG, $P, 3) . $VIDE); break; case 24: $COLOR = unpack("V", substr($IMG, $P, 3) . $VIDE); break; case 16: $COLOR = unpack("n", substr($IMG, $P, 2)); $COLOR[1] = $PALETTE[$COLOR[1] + 1]; break; case 8: $COLOR = unpack("n", $VIDE . substr($IMG, $P, 1)); $COLOR[1] = $PALETTE[$COLOR[1] + 1]; break; case 4: $COLOR = unpack("n", $VIDE . substr($IMG, floor($P), 1)); if (($P * 2) % 2 == 0) $COLOR[1] = ($COLOR[1] >> 4); else $COLOR[1] = ($COLOR[1] & 0x0F); $COLOR[1] = $PALETTE[$COLOR[1] + 1]; break; case 1: $COLOR = unpack("n", $VIDE . substr($IMG, floor($P), 1)); if (($P * 8) % 8 == 0) $COLOR[1] = $COLOR[1] >> 7; elseif (($P * 8) % 8 == 1) $COLOR[1] = ($COLOR[1] & 0x40) >> 6; elseif (($P * 8) % 8 == 2) $COLOR[1] = ($COLOR[1] & 0x20) >> 5; elseif (($P * 8) % 8 == 3) $COLOR[1] = ($COLOR[1] & 0x10) >> 4; elseif (($P * 8) % 8 == 4) $COLOR[1] = ($COLOR[1] & 0x8) >> 3; elseif (($P * 8) % 8 == 5) $COLOR[1] = ($COLOR[1] & 0x4) >> 2; elseif (($P * 8) % 8 == 6) $COLOR[1] = ($COLOR[1] & 0x2) >> 1; elseif (($P * 8) % 8 == 7) $COLOR[1] = ($COLOR[1] & 0x1); $COLOR[1] = $PALETTE[$COLOR[1] + 1]; break; default: return false; break; } imagesetpixel($res, $X, $Y, $COLOR[1]); $X++; $P += $BMP[\'bytes_per_pixel\']; } $Y--; $P+=$BMP[\'decal\']; } fclose($f1); return $res; } function changeBMPtoJPG($srcPathName){ $srcFile=$srcPathName; $dstFile = str_replace(\'.bmp\', \'.jpg\', $srcPathName); $photoSize = GetImageSize($srcFile); $pw = $photoSize[0]; $ph = $photoSize[1]; $dstImage = ImageCreateTrueColor($pw, $ph); $white = imagecolorallocate($dstImage, 255, 255, 255); //用 $white 颜色填充图像 imagefill( $dstImage, 0, 0, $white); //读取图片 $srcImage = ImageCreateFromBMP_private($srcFile); //合拼图片 imagecopyresampled($dstImage, $srcImage, 0, 0, 0, 0, $pw, $ph, $pw, $ph); $judge = imagejpeg($dstImage, $dstFile, 90); imagedestroy($dstImage); if($judge){ return $dstFile; }else{ return false; } } ?>
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