PHP generates BMP image like GD-php Tutorial

Generate BMP image like GD in PHP

Generate BMP image like GD in PHP Function imagebmp (& $ im, $ filename = '', $ bit = 8, $ compression = 0) { If (! In_array ($ bit, array (1, 4, 8, 16, 24, 32 ))) { $ Bit = 8; } Else if ($ bit = 32) // todo: 32 bit { $ Bit = 24; } $ Bits = pow (2, $ bit ); // Adjust the color palette Imagetruecolortopalette ($ im, true, $ bits ); $ Width = imagesx ($ im ); $ Height = imagesy ($ im ); $ Colors_num = imagecolorstotal ($ im ); If ($ bit <= 8) { // Color index $ Rgb_quad = ''; For ($ I = 0; $ I <$ colors_num; $ I ++) { $ Colors = imagecolorsforindex ($ im, $ I ); $ Rgb_quad. = chr ($ colors ['blue']). chr ($ colors ['green']). chr ($ colors ['red']). "\ 0 "; } // Bitmap data $ BMP _data = ''; // Non-compressed If ($ compression = 0 | $ bit <8) { If (! In_array ($ bit, array (1, 4, 8 ))) { $ Bit = 8; } $ Compression = 0; // The number of bytes in each row must be a multiple of 4. $ Extra = ''; $ Padding = 4-ceil ($ width/(8/$ bit) % 4; If ($ padding % 4! = 0) { $ Extra = str_repeat ("\ 0", $ padding ); } For ($ j = $ height-1; $ j> = 0; $ j --) { $ I = 0; While ($ I <$ width) { $ Bin = 0; $ Limit = $ width-$ I <8/$ bit? (8/$ bit-$ width + $ I) * $ bit: 0; For ($ k = 8-$ bit; $ k >=$ limit; $ k-= $ bit) { $ Index = imagecolorat ($ im, $ I, $ j ); $ Bin | = $ index <$ k; $ I ++; } $ BMP _data. = chr ($ bin ); } $ BMP _data. = $ extra; } } // RLE8 compression Else if ($ compression = 1 & $ bit = 8) { For ($ j = $ height-1; $ j> = 0; $ j --) { $ Last_index = "\ 0 "; $ Same_num = 0; For ($ I = 0; $ I <= $ width; $ I ++) { $ Index = imagecolorat ($ im, $ I, $ j ); If ($ index! ==$ Last_index | $ same_num> 255) { If ($ same_num! = 0) { $ BMP _data. = chr ($ same_num). chr ($ last_index ); } $ Last_index = $ index; $ Same_num = 1; } Else { $ Same_num ++; } } $ BMP _data. = "\ 0 \ 0 "; } $ BMP _data. = "\ 0 \ 1 "; } $ Size_quad = strlen ($ rgb_quad ); $ Size_data = strlen ($ BMP _data ); } Else { // The number of bytes in each row must be a multiple of 4. $ Extra = ''; $ Padding = 4-($ width * ($ bit/8) % 4; If ($ padding % 4! = 0) { $ Extra = str_repeat ("\ 0", $ padding ); } // Bitmap data $ BMP _data = ''; For ($ j = $ height-1; $ j> = 0; $ j --) { For ($ I = 0; $ I <$ width; $ I ++) { $ Index = imagecolorat ($ im, $ I, $ j ); $ Colors = imagecolorsforindex ($ im, $ index ); If ($ bit = 16) { $ Bin = 0 <$ bit; $ Bin | = ($ colors ['red']> 3) <10; $ Bin | = ($ colors ['green']> 3) <5; $ Bin | = $ colors ['blue']> 3; $ BMP _data. = pack ("v", $ bin ); } Else { $ BMP _data. = pack ("c *", $ colors ['blue'], $ colors ['green'], $ colors ['red']); } // Todo: 32bit; } $ BMP _data. = $ extra; } $ Size_quad = 0; $ Size_data = strlen ($ BMP _data ); $ Colors_num = 0; } // Bitmap file header $ File_header = "BM". pack ("V3", 54 + $ size_quad + $ size_data, 0, 54 + $ size_quad ); // Bitmap Header $ Info_header = pack ("V3v2V *", 0x28, $ width, $ height, 1, $ bit, $ compression, $ size_data, 0, 0, $ colors_num, 0 ); // Write a file If ($ filename! = '') { $ Fp = fopen ($ filename, "wb "); Fwrite ($ fp, $ file_header ); Fwrite ($ fp, $ info_header ); Fwrite ($ fp, $ rgb_quad ); Fwrite ($ fp, $ BMP _data ); Fclose ($ fp ); Return true; } // Browser output Header ("Content-Type: image/bmp "); Echo $ file_header. $ info_header; Echo $ rgb_quad; Echo $ BMP _data; Return true; }