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Learn about digital imaging
Digital imaging is the process of creating and manipulating digital images, typically from a physical object
Images have the power to inspire and stimulate ideas, demonstrate and realize concepts, inform, educate and instruct. Today, imaging is no longer a physical process of recording impressions, as digital technologies have revolutionized the creation and reproduction of all sorts of images.
Digital imaging is the process of creating and manipulating digital images, typically from a physical object. The term is often assumed to imply or include the processing, compression, storage, printing and display of such images. However, it is also used for other types of data such as radiation levels, topographic readings and sonic frequencies.
The digital format is easily stored on a wide range of media, and thus is easily transmitted without degradation. In fact, with digital imaging and optical and magnetic data storage, hours of video and audio can be stored on a medium that can fit in the pocket.
The electronic snapshots taken through a digital camera or scanned from documents such as photographs, manuscripts, printed texts and artwork are all raster images. In a Raster image, the image is converted into many small dots (pixels) that the eye blends to create the illusion of a complete image. From a distance, the image tends to “solidify.” Each pixel is assigned a tonal value (black, white, shades of gray or colour), which is represented in binary code (zeros and ones). The binary digits (“bits”) for each pixel are stored in a sequence by a computer and often reduced to a mathematical representation (compressed). The bits are then interpreted and read by the computer to produce an analog version for display or printing.
Vector images
In a vector digital image, the image is stored as shapes and vertices. Simply put, a vector image is defined by rectangles, circles, shapes, text and dimensions. Vector images have a much smaller file size as compared to raster images. They are best suited for web-based applications. Macromedia Flash is used to design vector images and animations.
Resolution
It is the ability to distinguish fine spatial details. The spatial frequency at which a digital image is sampled (the sampling frequency) is often a good indicator of resolution. This is why dots-per-inch (dpi) or pixels-per-inch (ppi) are common and synonymous terms used to express resolution for digital images. If a Raster image is enlarged, the dots that make up the image become blockish and the resolution starts deteriorating. However, when a vector image is enlarged, it maintains the same shape and detail.
Uses of digital imaging
Since a digital image is easy to transfer, therefore, it can be sent through wires, radio frequencies or even light frequencies (such as infrared). This means we can receive our favourite TV stations through airwaves or cable without using any reels of film.
For the people in the business of advertising, digital imaging is a dream come true. While not everyone would think so, digital imaging has made a huge impact on the art and world of photography. Once digital images are in the computer, the possibilities of manipulation are endless. In fact, it is possible the next Picasso might use a computer for his work.
Moreover, the use of digital imaging has become more commonplace in professional applications. Image editing software offer powerful tools for adding different annotations to highlight critical features, adding text for labels and assisting with page layouts for a professional look. In addition, the inclusion of digital images in learning materials can enrich and enhance both the content and the delivery of teaching.
Digital imaging has opened a new realm of art known as computer graphics. Computer graphics is a field that combines real art and photographs with digital paint or with completely computer-generated images. Computer graphics also includes 2D and 3D animations.
File formats
The most commonly used file formats include Bitmap (BMP), Portable Network Graphics (PNG), Joint Photographic Experts Group (JPEG), Graphics Interchange Format (GIF), Photo Shop Document (PSD), Shockwave Flash (SWF), Corel Draw (CDR), etc.
Compression
This is used to reduce the image file size for storage, processing and transmission. The file size for digital images can be quite large and thus taxing for the computing and networking capabilities of many systems. The most popular “compression file formats” are JPEGs and GIFs.
Digital enhancing
Digital image enhancing can do wonders for a poor quality image. Anyone can adjust image contrast or brightness on a home computer. Once restricted to expensive computers and equipment, the possibilities now are endless. The actual process of digital enhancing involves considering individual numbers representing the red, green and blue levels of the image and modifying them, based on a formula or algorithm. Digital enhancing includes steps such as descreening, despeckling, deskewing, sharpening, use of custom filters, and bit-depth adjustment. In some cases, the scanning software performs these steps. In others, separate image editing tools, for example, Adobe Photoshop and Corel Photo-Paint are used.
Digital editing
Digital editing includes selective editing of the image, rather than adjustment of the entire image (digital enhancing). This perhaps is what digital imaging is known for. By using a program like Adobe Photoshop, we can spray, paint, texturize and “clone” parts of an image to erase unwanted parts. The cloning or transfer tool copies from one part of an image onto another, assisting in the process of erasing. This is what the phrase “editing it out” means. With careful strokes of a digital brush, one can do quite a bit of digital magic. Other tools used in digital editing include rubber stamps, dodge burn, pencil, smear, impression, tint, posterize and solarize.
Using digital effects
Depending on the discretion of the digital artist, digital effects can be applied to selective parts of an image or on the total image. The most commonly used effect categories used for digital manipulation are as follows:
1. Arts and Crafts
2. Photographic
3. Colour Enhancements
4. Distortion
6. Overlays
7. Outlines
8. Paint
9. Sketch
10. Surface
11. 3D
12. Reflection
13. Illumination
From designing rich thematic illustrations to corporate logos, the scope of digital imaging is huge. Today, one cannot imagine a world without digital imaging. Without it, the world would be uninspiring and monotonous.
The writer
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