NCERT Class 12 Graphics Design Digital Imaging and Printing. Download NCERT Chapters and Books in pdf format. Easy to print and read. Copies of these textbooks may be downloaded and used as textbooks or for reference. Refer to other chapters and books at other links (NCERT now providing you soft copies of all textbooks of all subjects from class first to twelfth online).
Digital Imaging and Pinting
Graphic designers work with visual images, either for print media or for digital media. With the advent of computers, most of the graphic designer’s work is being done using computers. From graphical point of view there is a vast difference between images on paper such as drawings, sketches or photographs and images that you see on the screen of the computers. Images that are created, manipulated and displayed using computers are called digital images. Digital images are different from images drawn or painted on paper in many ways.
Types of Digital Images
There are two major categories of digital images: raster images and vector images. When images are stored in a computer in the form of a grid of basic picture elements called pixels, then these images are called raster images. The pixels contain the information about colour and brightness. Image-editing programmes can replace or modify the pixels to edit the image in various ways. The pixels can be modified in groups, or individually. There are sophisticated algorithms to achieve this.
On the other hand vector images are stored as mathematical descriptions of the image in terms of lines, Bezier curves, and text instead of pixels. This is the main difference between raster and vector images. However, this difference is responsible for the development of two major categories of graphic technologies namely: Raster Graphics and Vector Graphics. Therefore, the image-editing software used by the practicing graphic designers falls under one of these categories.
Since the Vector images are in the form of mathematical descriptions of the basic components of an image, it is easy to modify and manipulate them as well as transform them into Raster images. Vector images are easily scalable to any resolution. Major problem is that though vector images are mathematically precise many a times a graphic artist feels that the graphic quality is compromised. Raster images can also be manipulated and modified in various ways but transformation of a raster image into a vector image requires sophisticated computational algorithms. Raster images are comparatively more precise visually.
Digital Image Editing
Graphic designers frequently use both the types of digital images. There are tools to convert images on the papers into digital images. These devices are called scanners. Such digital images can be further modified or manipulated digitally. There are software programs to create, modify and manipulate digital images. Such programs are called digital image editors. There are digital image editors for two dimensional image processing as well as three dimensional image processing. Using digital image editors, a variety of operations on the images are possible. Some of the common operations are discussed are as follows:
Image manipulation requires selecting either a part of the image or the entire image to make changes. If you select the entire image then you can change the orientation, size, colour etc. If you select a part of the image then all the changes you wish to make will be applicable to selected part. Therefore ‘selection’ is the basic operation in digital image making. Various image editors provide number of ways to select either the whole image or part of the image.
Layer is another most basic but equally important feature of digital image making. Idea of layers is very simple. If you draw a part of the image on one transparent paper and then draw rest of the parts of the image on separate transparent papers and finally put these transparent papers on each other, so that you will see a complete image. Layers are just like transparent sheets of papers, only difference is that they are digitally transparent layers. Since parts of the digital image are separated in terms of separate layers it provides tremendous flexibility for manipulation of the digital image.
- The top layer (the bird) is moved to the left.
- The top layer is moved to the right.
- The top layer (the bird) is partially transparent, so the background can be seen clearly through its wing.
1. What are the differences between Vector images and Raster images.
2. What are the advantages of using layers in the imageediting software.
3. Which are the software you have been using of images. Compare any two by giving their advantages and disadvantages.
Please refer to attached file for NCERT Class 12 Graphics Design Digital Imaging and Printing
Click for more Graphics Design Study Material ›