Structure of bmp file

The term "device independent" means that the bitmap specifies pixel color in a form independent of the method used by a display to represent color. This file format can be stored uncompressed, so reading BMP files is fairly simple; most other graphics formats are compressed, and some, like GIF, are difficult to decompress. Below is a more detailed table of the contents of each of these structures. Each scan line is zero padded to the nearest 4-byte boundary.

If the image has a width that is not divisible by four, say, 21 bytes, there would be 3 bytes of padding at the end of every scan line. Instead of storing a value for each pixel RLE stores a number, N, followed by an index.

This means that the next N pixels are of the color for this index. Each pixel in the bitmap data stores a single value used as an index into the colour palette.

The colour information stored in the element at that index specifies the colour of that pixel. Availability of colour in a bitmap file varies as follow:.

Bitmap pixels are stored as bits packed in rows where the size of each row is rounded up to a multiple of 4 bytes a bit DWORD by padding. The total amount of bytes required to store the pixels of an image can not be directly calculated by just counting the bits. Since there is padding involved, the effect of round up the size of each row to a multiple of 4 bytes is required.

Padding bytes not necessarily 0 are to be appended to the end of the rows in order to bring up the length of the rows to a multiple of four bytes. When the pixel array is loaded into memory, each row must begin at a memory address that is a multiple of 4.

Pixel formats and their implications are as listed below:. Table of Content. What is a BMP file? Home Contact Privacy. Terms related to bmp file format :. Source s : Wikipedia Table Creative Commons.

It would be very appreciated if you give me advice even about one particular topic for example load the file. However, I'd recommend using C , then the task would be trivial with the System. Drawing namespace. This function is used for loading a bmp file to memory. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?

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