Digital Image Processing

 Digital Image:
  • A digital image is a representation of a two dimensional image as a finite set of digital values, called picture elements or pixels.


  • Pixel values typically represent gray levels, colours, heights, opacities etc.
  • Remember digitization implies that a digital image is an approximation of a real scene.


 Digital Image Processing:
  • Digital image processing focuses on two major tasks.
  • Improvement of pictorial information for human interpretation.
  • Processing of image data for storage, transmission and representation for autonomous machine perception.
 Phases of Image Processing:


 1. Acquisition: It could be as simple as being given an image which is in digital form. It involves two steps i.e,. Scaling and color  conversion.
 2. Image Enhancement: It is amongest the simplest and most appealing in areas of image processing it is also used to extract some  hidden details from an image and is subjective.
 3. Image Restoration: It also deals with appealing of an image but it is objective(Restoration is based on mathematical or probabilistic  model or image degradation). 
 4. Morphological Processing: It deals with tools for extracting image components that are useful in the representation and  description of shape.
 5. Segmentation: It includes partitioning an image into its constituent parts or objects. Autonomous segmentation is the most difficult  task in image processing. 
 6. Object Recognition: It is a process that assigns a label to an object based on its descriptor.
 7. Representation and Description: It follows output of segmentation stage, choosing a representation is only the part of solution for  transforming raw data into processed data.
 8. Image Compression: It involves in developing  some functions to perform this operation. It mainly deals with image size or  resolution.
 9. Colour Image Processing: It deals with pseudocolor and full color image processing color models are applicable to digital image  processing.  
 Real Time Applications:
  • The use of digital image processing techniques has exploded and they are now used for all kinds of tasks in all kinds of areas
                     –  Image Sharpening and restoration
                     –  Medical Visualization
                     –  Industrial Inspection
                     –  Machine/ Robot Vision
                     –  Artistic Effects
Used to Improve Quality and Remove Noise
Used for Boundary Detection(Original MRI Image of Dog Heart vs Edge Detection) 
Used for Number Plate Recognition for Speed Cameras
Used in Finger Print Recognition
Used in Artistic Effects to Make Images More Visually Appealing

 Advantages:
  • It improves the visual quality of an image and the distribution of intensity.
  • It can process an image in such a way that the result is more suitable than the original image.
  • An image can be easily modified using a number of techniques.
 Disadvantages:
  • Digital cameras which are used for digital image processing have some drawbacks like memory card problems, higher cost, battery consumption.