Introduction to Digital Image
It is a type of image which is formed from pixels. Each pixel has some finite size and is represented by some finite intensity to show the image. The pixels are set of a properly arranged rectangular array. The image size can be determined by the pixel array dimensions. It has finite coordinates i.e. x-coordinate and y-coordinate. It is of two types i.e. raster type and vector type. The raster image is basically used for reference to a digital image.
What is Digital Image?
It is the type of image which is made of pixels. It includes printed texts, photographs, and artwork. It is captured from the digital camera, any image machine. As it is made up of pixels it is used to define the quality of the image. The pixel value is used to measure the quality of the image. The binary code is used to represent the value of a pixel. The resolution can be measured by the value of pixel per inch value. For storing it in the computer there are different file formats used which are TIFF, GIF, JPEG, BMP.
The formats used for storing the digital image are discussed below:
JPEG
The full form of JPEG is the Joint Photographic Experts Group. The JPEG format is used to store the information in a small size of the file. The digital camera produces the digital image in the format of JPEG because the file size is smaller for JPEG format. JPEG is not used when the image is used as logos or drawings as the image is in compressed form and when it is zoomed the quality of the image gets decreased.
TIFF
The full form of TIFF is the Tagged Image File Format. The file size of TIFF digital image format is comparatively large from the JPEG format. The file size is larger because the images are present in uncompressed form. The photo software produces the TIFF format image in Photoshop.
PNG
The full form of PNG is Portable Network Graphics. Most web images present on the internet is present in the format of PNG. The PNG format is not used as the file size is larger for PNG images compare to JPEG images. But the image of text is of small size with great quality of image resolution. When any user takes the screenshot of the screen of a computer the image is stored in the format of PNG. As the image is a mixed image that contains text and pictures the image is stored in the format or PNG format.
Types of Digital Image
It can be basically categorized into two categories i.e.
- Vector Digital Image
- Raster Digital Image
1. Vector Digital Image
- It is made up of lines and curves which are called paths. The computer software is used for creating vector graphics. The vector image represents the wireframe type of image. The lines include in the wireframe type of image have specific node locations, node positions, curves, and lines. The lines and curves used in it can be allocated a specific color value. Using this formulaic equation, each image dimension can be controlled without compromising from the image resolution, and It can be scaled and the pixels.
- The vector image can be zoomed but the pixel quality will not be compromised which makes the vector image distinguishable from other types of image. The curves of the image are smooth and can be easily be zoomed. The best example is the text. Whenever the text is zoomed no matter what the pixel quality does not decrease and the zoomed text looks exactly the same as of its original size. The other advantage is the file-size efficiency of the image. The file size is very less which makes it easily transmittable from one computer to another computer.
- One of the disadvantages is the compatibility of the vector image. When any program is used to create it is saved as the native file of that [program which makes it less compatible as the program needs to be installed in destination computer also to get access to it. An example is illustrations which are like photographs that can be made from vector image programs.
2. Raster Digital Image
- The other name of the raster image is a bitmap image. It is called a bitmap image because it is made up of billions and trillions of tiny squares known as pixels. When the bitmap image is zoomed the tiny squares can be seen in it. When it is compared with a vector the main difference is file size efficiency. It has a larger file size comparer to a vector. The file size is larger because of pixels per inch (PPP) and dots per inch (DPI).
- The software used to create it makes the size larger as it tracks each pixel of an image. This makes it less usable as the file size creates a problem to store on the computer and make it less usable. It is used to create the photographs. It is created when the photograph is taken from the digital camera.
- An example of a raster image is the images present on the websites. The raster images are mostly used for the digital publication but cannot be used for the printed type projects. The raster images cannot be used for printed projects as the resolutions of image decreased as the file size is larger for it.
Conclusion
It is formed from the pixels and the device used to capture the digital image is a digital camera and image machine. It can be categorized into two categories i.e. raster and vector type image. It has a different file format in which the image is stored in the computer. The file formats are PNG, JPEG, GIF, TIFF, and BMP.
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