php代码:
/** * BMP 创建函数 * @author simon * @param string $filename path of bmp file * @example who use,who knows * @return resource of GD */ function imagecreatefrombmp( $filename ){ if ( !$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'] ){ if ( $BMP['bits_per_pixel'] == 32 ){ $COLOR = unpack( "V", substr( $IMG, $P, 3 ) ); $B = ord(substr($IMG, $P,1)); $G = ord(substr($IMG, $P+1,1)); $R = ord(substr($IMG, $P+2,1)); $color = imagecolorexact( $res, $R, $G, $B ); if ( $color == -1 ) $color = imagecolorallocate( $res, $R, $G, $B ); $COLOR[0] = $R*256*256+$G*256+$B; $COLOR[1] = $color; }elseif ( $BMP['bits_per_pixel'] == 24 ) $COLOR = unpack( "V", substr( $IMG, $P, 3 ) . $VIDE ); elseif ( $BMP['bits_per_pixel'] == 16 ){ $COLOR = unpack( "n", substr( $IMG, $P, 2 ) ); $COLOR[1] = $PALETTE[$COLOR[1] + 1]; }elseif ( $BMP['bits_per_pixel'] == 8 ){ $COLOR = unpack( "n", $VIDE . substr( $IMG, $P, 1 ) ); $COLOR[1] = $PALETTE[$COLOR[1] + 1]; }elseif ( $BMP['bits_per_pixel'] == 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]; }elseif ( $BMP['bits_per_pixel'] == 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]; }else return FALSE; imagesetpixel( $res, $X, $Y, $COLOR[1] ); $X++; $P += $BMP['bytes_per_pixel']; } $Y--; $P += $BMP['decal']; } fclose( $f1 ); return $res; }