What is Bitmap?

A bitmap refers to the particular graphic file format. It uses the extensions .bmp (bitmap) or .dib (device-independent bitmap) and is used mainly in Microsoft Windows and OS/2. It also refers to a raster or bitmapped image format.

Technically, this is an image file format that allows creating and storing computer graphics. The file actually contains a lot of tiny dots in a specific pattern that creates an image when viewed from a distance.

Understanding Bitmap

What is Bitmap

A bitmap simply refers to a file format or a memory organization that consists of rows and columns of bits, called pixels. These pixels are usually squares created by bits.

The primary purpose of developing the bitmap format by Microsoft in the 1980s was to provide the users with images that are application or device-independent.

It also offers the users a useful and easy way to use a small amount of memory to keep track of it for a bitmap table.

A bitmap is also known by different names, such as:

Usually, the bitmap files are larger in size. That is why it is not used commonly outside of the Microsoft Windows setting.

There are different types of bitmaps, as you will come to know about them in the later section, but apart from BMP, every other format implements a compression algorithm to ensure that the bitmaps are smaller and it is easier to transfer them across the internet.


The pixel can be Black and White or colored, which is typically determined by the number of bits, such as:

There are often tens of thousands of these bits, which collectively display the image.

The density of the squares or pixels determines the resolution of the bitmap. For example, if a computer monitor has a resolution of 800 × 600, it means that:

When the number of pixels is higher, the image will be more realistic and clearer.


There are different ways in which a bitmap image can be saved, such as:


Typically, for making changes in the files to store and transfer, data compression is used in bitmaps.

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However, if the files are compressed excessively, there may be a loss of pixels in the final image. It will make the image look more pixelated, and in it, you can see that:

On the other hand, if the compression is lower, the bitmap will be more intact and will look pretty much the same as the original.


The size of the units in bitmaps is very important. Utmost care should be taken while selecting the unit size, due to the following reasons:

There is no need to select a large size for the units because, even with a small unit size of, say, 3 bytes, a single bit of the bitmap can denote 24 bits.

This is because the size of the bitmap depends entirely on the size of the memory unit as well as the memory.

However, the problem arises when an ‘n’ size memory block in the bitmap is required to be engaged by a process.

In such a situation, a ‘n’ size vacancy with all zero values will be required in the bitmap.

What are the Features of Bitmap?

Ideally, there are two specific features of a bitmap namely, the resolution or number of pixels, and the color depth for each pixel.

However, there are also a few other notable features of a bitmap, such as:

They create beautiful images since they store a lot of information about an image at maximum resolution.

How Many Types of Bitmap Images are There?

There are five major types of bitmap images. However, there are also a few others that are used in specific types of systems.

These are Bitmap or BMP, Graphics Interchange Format or GIF, Joint Photographic Experts Group or JPEG, Portable Network Graphics or PNG, Tag Image File Format or TIFF, Exchangeable Image File or EXIF, X BitMap or XBM used in X Window systems, and PiCture eXchange or PCX.

Each of these types can be distinguished by their respective features, as explained below.







Bitmap Vs Vector

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Questions & Answers:

Why is Bitmap Used?

One of the main reasons to use bitmaps in your image design is that the file will contain loads of color information in the form of uncompressed data. This is ideal for storing and displaying digital images of high quality.

This will be very helpful when working with images or photographs that need to look real since you will be able to access a much wider range of rich colors to use for transitions and more.

How Many Bits are There in a Bitmap?

Usually, the number of bits in a bitmap file is detailed in the file header. It can be varied, such as 1, 4, 8, 15, 24, 32, or 64 bit per pixel, but a bitmap with 24 bits per pixel is used most commonly.

What is the Size of a Bitmap File?

The size of the bitmap file would typically depend on the way the individual pixels are handled. Usually there are a few dimensional restraints to a bitmap file, which may max out at 4 GB.

What are Bitmap Images Made Up of?

Typically, the bitmap images are made up of pixels instead of lines. This means that when you zoom a bitmap image it will be grainy, instead of being sharp or smooth.

Where are Bitmap Images Stored?

In a computer, the bitmap images are stored where every other thing is stored, that is, in a file system on the hard disk as a file.

It may be stored as an entire image in a file, or sometimes it may be stored as a part of the content in a file. The image is stored in a compressed format as a quadrangular grid of pixels.


Bitmap or raster images are typically made up of pixels or small dots of diverse colors, set in a proper manner to create an image.

Ideally, it is the arrangement of the pixels in a bitmap image that makes it easy to use. It is highly dependent on the resolution and therefore changes in it may result in a loss of image quality.