Friday, 17 May 2019

Applications of Digital Image Processing

Applications
1.      Intelligent Transportation Systems – This technique can be used in Automatic number plate recognition and Traffic sign recognition.
 
2.      Remote Sensing – For this application, sensors capture the pictures of the earth’s surface in remote sensing satellites or multi – spectral scanner which is mounted on an aircraft. These pictures are processed by transmitting it to the Earth station. Techniques used to interpret the objects and regions are used in flood control, city planning, resource mobilization, agricultural production monitoring, etc.
 
3.      Moving object tracking – This application enables to measure motion parameters and acquire visual record of the moving object. The different types of approach to track an object are:
·            Motion based tracking
·            Recognition based tracking
 
4.      Defense surveillance – Aerial surveillance methods are used to continuously keep an eye on the land and oceans. This application is also used to locate the types and formation of naval vessels of the ocean surface. The important duty is to divide the various objects present in the water body part of the image. The different parameters such as length, breadth, area, perimeter, compactness are set up to classify each of divided objects. It is important to recognize the distribution of these objects in different directions that are east, west, north, south, northeast, northwest, southeast and south west to explain all possible formations of the vessels. We can interpret the entire oceanic scenario from the spatial distribution of these objects.
 
5.      Biomedical Imaging techniques – For medical diagnosis, different types of imaging tools such as X- ray, Ultrasound, computer aided tomography (CT) etc are used. The diagrams of X- ray, MRI, and computer aided tomography (CT) are given below.
 
Representational Image Of X- ray, MRI, and computer aided tomography (CT)
 
Fig. 2: Representational Image Of X- ray, MRI, And Computer Aided Tomography (CT)
 
Some of the applications of Biomedical imaging applications are as follows:
·               Heart disease identification– The important diagnostic features such as size of the heart and its shape are required to know in order to classify the heart diseases. To improve the diagnosis of heart diseases, image analysis techniques are employed to radiographic images.
·               Lung disease identification – In X- rays, the regions that appear dark contain air while region that appears lighter are solid tissues. Bones are more radio opaque than tissues. The ribs, the heart, thoracic spine, and the diaphragm that separates the chest cavity from the abdominal cavity are clearly seen on the X-ray film.
·               Digital mammograms – This is used to detect the breast tumour. Mammograms can be analyzed using Image processing techniques such as segmentation, shape analysis, contrast enhancement, feature extraction, etc. 
 
6.      Automatic Visual Inspection System – This application improves the quality and productivity of the product in the industries.
·               Automatic inspection of incandescent lamp filaments – This involves examination of the bulb manufacturing process. Due to no uniformity in the pitch of the wiring in the lamp, the filament of the bulb gets fused within a short duration. In this application, a binary image slice of the filament is created from which the silhouette of the filament is fabricated. Silhouettes are analyzed to recognize the non uniformity in the pitch of the wiring in the lamp. This system is being used by the General Electric Corporation.
 
·               Automatic surface inspection systems – In metal industries it is essential to detect the flaws on the surfaces. For instance, it is essential to detect any kind of aberration on the rolled metal surface in the hot or cold rolling mills in a steel plant. Image processing techniques such as texture identification, edge detection, fractal analysis etc are used for the detection.
 
·               Faulty component identification – This application identifies the faulty components in electronic or electromechanical systems. Higher amount of thermal energy is generated by these faulty components. The Infra-red images are produced from the distribution of thermal energies in the assembly. The faulty components can be identified by analyzing the Infra-red images.
 

Digital Image Processing Important Questions

UNIT – I
DIGITAL IMAGE FUNDAMENTALS & IMAGE TRANSFORMS

    Part-A--Two Mark Questions:
    1. Define Image.How do you represent the digital images?
    2. Define Pixel or picture elements.
    3. Steps in DIP.
    4. Elements of DIP.
    5. Brightness adaptation and discrimination.
    6. Difference between rods and cones.
    7. Weber ratio
    8. Mach band effect
    9. Simultaneous contrast
    10. List the hardware-oriented color models.
    11. Sampling and quantization
    12. Zooming and shrinking.
    13. Moiré pattern
    14. False contouring
    15. Dither
    16. Checker board effect
    Part--B-Big Questions:
    1. List the steps involved in digital image processing
    2. Elements or components of DIP
    3. Elements of Visual perception
    4. Digital camera & Vidicon camera
    5. Image sampling and quantization (How an analog image can be converted to digital?)
    6. Image Sensing and acquisition devices 


    UNIT – 2
    Two Mark Questions:
    1. Define image enhancement.
    2. Gray level transformation
    3. Contrast stretching & gray level slicing.
    4. Thresholding
    5. Histogram
    6. Histogram equalization & specification
    7. Smoothing filter
    8. Sharpening filter
    9. Spatial filter
    10. Derivative filter types
    11. Robert cross, Prewitt & Sobel operators
    12. Unsharp masking
    13. High boost filtering
    14. Frequency domain filtering
    15. Homomorphic filtering
    Big Questions:
    1. Histogram equalization
    2. Histogram specialization
    3. Spatial smoothing filter: Linear & Non-Linear
    4. Spatial sharpening filter
    5. Homomorphic filter

    UNIT -3
    Two Mark Questions:
    1. Draw image degradation model.
    2. Median filter
    3. Order statistics filter
    4. Inverse filtering
    5. Wiener filtering/ LMS filtering
    6. Blind image restoration
    7. How edges are detected in an image?
    8. Zero crossing property
    9. LoG/Mexican hat function
    10. Thresholding
    11. Region growing, splitting and merging
    12. Watershed segmentation
    13. Catchment Basin (or) Watershed
    14. Markers
    15. How dams are constructed in watershed?
    16. Drawbacks of Watershed
    Big Questions:
    1. Image restoration/degradation models
    2. Spatial restoration filters: Mean, Order statistics and Adaptive
    3. Frequency restoration filters: Band reject, Band pass, Notch and Optimum Notch
    4. Restoration filter: Inverse and Wiener/LMS filters

    UNIT-4
    Two Mark Questions:
    1. What is the need of Wavelet Transform?
    2. What is MRA?
    3. Difference between Lossless and Lossy compression.
    4. Types of redundancy& its definition
    5. Define compression ratio
    6. Define block and instantaneous code
    7. Huffman coding
    8. Arithmetic coding
    9. JPEG
    10. MPEG
    11. I – frame, P- frame and B-frame definition
    12. Zig-Zag sequence
    13. Vector quantization
    Big Questions:
    1. Lossless predictive coding
    2. Lossy predictive coding: Vector quantization and transform coding
    3. JPEG: Encoder& Decoder
    4. JPEG 2000
    5. MPEG

    UNIT-5
    Two Mark Questions:
    1. Define chain codes
    2. Define polygonal approximation
    3. Define boundary segment
    4. Name few boundary descriptors
    5. Define shape numbers
    6. Define texture
    7. Define pattern and pattern class
    8. Define regional descriptors
    9. Topological descriptors
    10. Fourier descriptors

    Big Questions:
    1. Chain codes
    2. Polygonal approximation and MPP algorithm
    3. Signature and boundary segments
    4. Regional descriptors & topological descriptors
    5. How the tree approach is used to describe different regions of an image?