Bitmap

For other uses, see Bitmap (disambiguation).

In computing, a bitmap is a mapping from some domain (for example, a range of integers) to bits. It is also called a bit array or bitmap index.

As a noun, the term "bitmap" is very often used to refer to a particular bitmapping application: the pix-map, which refers to a map of pixels, where each one may store more than two colors, thus using more than one bit per pixel. In such a case, the domain in question is the array of pixels which constitute a digital graphic output device (a screen or monitor). In some contexts, the term bitmap implies one bit per pixel, whereas pixmap is used for images with multiple bits per pixel.

A bitmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to the similar concept of a spatially mapped array of pixels. Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or memory.

Many graphical user interfaces use bitmaps in their built-in graphics subsystems; for example, the Microsoft Windows and OS/2 platforms' GDI subsystem, where the specific format used is the Windows and OS/2 bitmap file format, usually named with the file extension of .BMP (or .DIB for device-independent bitmap). Besides BMP, other file formats that store literal bitmaps include InterLeaved Bitmap (ILBM), Portable Bitmap (PBM), X Bitmap (XBM), and Wireless Application Protocol Bitmap (WBMP). Similarly, most other image file formats, such as JPEG, TIFF, PNG, and GIF, also store bitmap images (as opposed to vector graphics), but they are not usually referred to as bitmaps, since they use compressed formats internally.

Pixel storage

In typical uncompressed bitmaps, image pixels are generally stored with a variable number of bits per pixel which identify its color, the color depth. Pixels of 8 bits and fewer can represent either grayscale or indexed color. An alpha channel (for transparency) may be stored in a separate bitmap, where it is similar to a grayscale bitmap, or in a fourth channel that, for example, converts 24-bit images to 32 bits per pixel.

The bits representing the bitmap pixels may be packed or unpacked (spaced out to byte or word boundaries), depending on the format or device requirements. Depending on the color depth, a pixel in the picture will occupy at least n/8 bytes, where n is the bit depth.

For an uncompressed, packed within rows, bitmap, such as is stored in Microsoft DIB or BMP file format, or in uncompressed TIFF format, a lower bound on storage size for a n-bit-per-pixel (2ⁿ colors) bitmap, in bytes, can be calculated as:

${\text{size}}={\text{width}}\cdot {\text{height}}\cdot n/8$

where width and height are given in pixels.

In the formula above, header size and color palette size, if any, are not included. Due to effects of row padding to align each row start to a storage unit boundary such as a word, additional bytes may be needed.

Device-independent bitmaps and BMP file format

Main article: BMP file format

Microsoft has defined a particular representation of color bitmaps of different color depths, as an aid to exchanging bitmaps between devices and applications with a variety of internal representations. They called these device-independent bitmaps as DIBs, and the file format for them is called DIB file format or BMP file format. According to Microsoft support:

A device-independent bitmap (DIB) is a format used to define device-independent bitmaps in various color resolutions. The main purpose of DIBs is to allow bitmaps to be moved from one device to another (hence, the device-independent part of the name). A DIB is an external format, in contrast to a device-dependent bitmap, which appears in the system as a bitmap object (created by an application...). A DIB is normally transported in metafiles (usually using the StretchDIBits() function), BMP files, and the Clipboard (CF_DIB data format).

Here, "device independent" refers to the format, or storage arrangement, and should not be confused with device-independent color.

Other bitmap file formats

Main article: Image file formats

The X Window System uses a similar XBM format for black-and-white images, and XPM (pixelmap) for color images. Numerous other uncompressed bitmap file formats are in use, though most not widely. For most purposes standardized compressed bitmap files such as GIF, PNG, TIFF, and JPEG are used; lossless compression in particular provides the same information as a bitmap in a smaller file size. TIFF and JPEG have various options. JPEG is usually lossy compression. TIFF is usually either uncompressed, or lossless Lempel-Ziv-Welch compressed like GIF. PNG uses deflate lossless compression, another Lempel-Ziv variant.

There are also a variety of "raw" image files, which store raw bitmaps with no other information; such raw files are just bitmaps in files, often with no header or size information (they are distinct from photographic raw image formats, which store raw unprocessed sensor data in a structured container such as TIFF format along with extensive image metadata).

Digital Ownership of a Bitcoin Blockchain Block by using the Bitmap Standard

Main article: Bitmap Standard on the Bitcoin Blockchain

Intro to the Bitmap Standard

A bitmap inscription is a mechanism to claim ownership of a Bitcoin block by inscribing it onto a Satoshi using Ordinals theory and the Bitmap standard. The Bitmap theory is an open-source standard that allows anyone to ascribe ownership of a Bitcoin Block by inscribing it onto a Satoshi using Ordinals theory and the Bitmap standard.

The Bitmap Theory

The Bitmap theory 101 proposes for a decentralised Metaverse and offers a ground breaking way to claim ownership of Bitcoin Blockchain Blocks. The bitmap Theory was created by Bitoshi Blockamoto. With Bitmap, any block on the Bitcoin blockchain can be inscribed. Being the first claim to ownership of a bitmap or by purchasing the rights of the bitmap on the secondary market, the owner will have the ownership of the bitcoin block. It works similar to how a physical property or parcel of land has a title deed to claim the right of ownership.

Each Bitcoin Block is considered a district and has a number of transactions within the block which are known as parcels. Owners can inscribe transactions as parcels on their own blocks, effectively fractionalizing a block and making it possible to distribute parts of it to a wider community. This means that block owners can become active contributors to the Metaverse, offering a platform for building upon their blocks and creating vibrant, community-driven spaces.

The Bitmap standard sets the protocol for digital land/realm ownership on the Bitcoin Blockhain. These potential new realms and worlds can be created on and off chain.

In summary, a Bitmap inscription is an innovative way to claim digital ownership of Bitcoin Blocks using Ordinals theory and the Bitmap standard. It has opened up new possibilities for open-source development and for decentralised community-driven spaces in the Metaverse.

Notes

See also

• Free space bitmap, an array of bits that tracks which disk storage blocks are in-use
• Raster graphics
• Raster scan
• Rasterization
• Sprite (computer graphics)
• Voxels
• Vector graphics
• Image tracing