BMP

Ing BMP o BMP file format, a ausan da mu namang bitmap o DIB file format (para device-independent bitmap), metung yang image file format a magagamit ba lang isimpan o isinup deng larawan a digital, lalu na kareng operating system a Microsoft Windows ampong OS/2.

Dakal la reng graphical user interface a gagamit bitmap kareng karelang built-in graphics subsystems;^[1] alimbawa, king GDI subsystem da reng platform a Microsoft Windows ampong OS/2, nung nu ing partikular a format a magagamit ya pin ing Windows and OS/2 bitmap file format, a keraklan dirinan dang lagiu ning file extension ning .BMP o .DIB.

Kareng simpan a BMP a e makasiksik (uncompressed BMP files), at dakal pang aliwang file format a bitmap, misisimpan la reng pixel da reng larawan (image pixels) a maki color depth a 1, 4, 8, 16, 24, o 32 bit balang pixel (bits per pixel). Den namang larawan a 8 bits o mas ditak, maliari la king grayscale o indexed color. Maliari yang isimpan ing metung a alpha channel (para king transparency) king aliwang simpan o file, nung nu ne kawangis ning larawan a grayscale, o king kapat a channel a manalili kareng larawan a 24-bit king 32 bits per pixel.

Deng simpan a bitmap a e makasiksik (anti ing BMP), misna la karagul kesa kareng file format a makasiksik o compressed (king sanu man kareng miyayaliwang paralan) para king pareung larawan. Alimbawa, ing Wikipedia logo a 1058×1058, a maki dagul a manga 287.65 KB king PNG format, 3358 KB ya nung metung yang 24-bit a BMP file. Keraklan, e la bage king pamanalis king [[w:Internet}Aptas]] (Internet) o kareng media.a mangabagal o limitadu king agiu rang dalan.

Paka-ayus la kareng dane (rows) deng bit a magdala kareng bitmap pixel. Dependi king color depth, gumamit yang e kumulang king n/8 bytes (n ing bit depth, uling ing metung a byte katumbas ya king walung bit). Maliari yang tantian ing dagul ning BMP file a n-bit (2ⁿ colors), kayabe ne ing epektu ning pamagumpisa ning balang kataya king angganan a 32-bit, anti kaniti:

${\displaystyle {\mbox{rowsize}}=4\cdot {\Big \lfloor }{\frac {(n\cdot {\mbox{width}})+31}{32}}{\Big \rfloor }}$, nung nu ing floor function, bibie ne ing least integer a e lati king argument; a ya pin ing bilang da reng dword a 32-bit nung nu ya maliaring ipalub ing metung a dane da reng n-bit pixel; parakalan (multiply) meng makatapat iti, at akua me ing bilang da reng JOBBIES.

${\displaystyle {\mbox{filesize}}\approx 54+4\cdot 2^{n}+{\mbox{rowsize}}\cdot {\mbox{height}}}$,

nung nu ing tas (height) ampo ing lapad (width) masusukad la kareng pixel.

Ketang formula king babo, ing 54 kasindagul ne ning header king pkabaluan a Windows V3 BMP version (14-byte BMP file header plus 40-byte DIB V3 header); ating aliwang header version a mas maragul o malati kesa kanita. At ing ${\displaystyle 4\cdot 2^{n}}$ kasindagul ne ning color palette; metung yang tantia ing dagul a ini, uling ${\displaystyle 3\cdot 2^{n}}$ bytes ya ing dagul ning color palette king OS/2 V1 version. Den namang aliwang version, dependi ing pamituldu (pamag-define) da king bilang da reng kuleng kailangan ning larawan. Mapaliaring mas ditak la reti kesa king ${\displaystyle 2^{n}}$.^[2] Bukud mung deng simpan a maki walu o mas ditak a bits per pixel ing gagamit palette; alimbawa, para kareng bitmap a 16-bit (o mas matas), idayu ya itang dakeng tungkul king palette king pamag-karkula:

${\displaystyle {\mbox{filesize}}\approx 54+{\mbox{rowsize}}\cdot {\mbox{height}}}$

Uling simpli ya ing file format a BMP, uling balu reng balu deng gagamit king Windows ampo reng aliwa, uling dakal a misusulat tungkul kaniti, at alang makaing pigaganakan a patent, metung yang maralas magagamit a format, a akikilala da reng image processing program ibat kareng dakal a operating system.

Lipat ning mangaragul la reng simpan a BMP uling ala lang nanumang pangasiksik o compression, maliari nong isiksikdeng dakal a simpan a BMP kapamilatan da reng algorithm a maki lossless data compression, alimbawa ing ZIP, uling maki ulit-ulit la o redundant a data deti.

Pun bulung: Image file formats

Kayawig ne ning BMP ing X Window System, a maki XBM format para kareng larawan a black-and-white, ampong XPM (pixelmap) para kareng larawan a maki kule. Atin muring miyayaliwang format a "raw" o e meprosesu, a mag-save king raw data a yalang aliwang impormasiun. Magagamit la murin deng format a Portable Pixmap (PPM) ampong Truevision TGA, oneng e la masiadung magagamit, o gagamit da la mu para kareng espesial a sangkan. Alimbawa, maliari yang magdalang impormasiun tungkul king transparency ing TGA.

Dakal la pa reng aliwang bitmap file format a magagamit da, oneng e ro gagamitan deti deng keraklan.^[3]

• Comparison of graphics file formats
• Microsoft Paint, a built-in Windows bitmap editor

• For a table view of the bitmap file format at sourceforge
• Bitmap File Structure
• Wotsit.org's entry on the BMP format Archived Pebreru 22, 2008 at the Wayback Machine
• An introduction to DIBs (Device Independent Bitmaps)
• Example BMP images with various internal formats Archived Juniu 25, 2006 at the Wayback Machine
• Bitmap image info
• List of programs that support .BMP file
• Bitmap entries at File-extensons.org