INTERVIEW AND SHORT ANSWER QUESTION ON IMAGE PROCESSING-BIOMEDICAL JOBS & NOTES-QUESTION NO 1-20

Define Image?
An image may be defined as two dimensional light intensity function f(x, y)
where x and y denote spatial co-ordinate and the amplitude or value of f at any point
(x, y) is called intensity or grayscale or brightness of the image at that point.

2. What is Dynamic Range?
The range of values spanned by the gray scale is called dynamic range of an
image. Image will have high contrast, if the dynamic range is high and image will have
dull washed out gray look if the dynamic range is low.
3. Define Brightness?
Brightness of an object is the perceived luminance of the surround. Two objects
with different surroundings would have identical luminance but different brightness.
4. Define Tapered Quantization?
If gray levels in a certain range occur frequently while others occurs rarely, the
quantization levels are finely spaced in this range and coarsely spaced outside of it. This
method is sometimes called Tapered Quantization.
5. What do you meant by Gray level?
Gray level refers to a scalar measure of intensity that ranges from black to grays
and finally to white.
6. What do you meant by Color model?
A Color model is a specification of 3D-coordinates system and a subspace within
that system where each color is represented by a single point.
7. List the hardware oriented color models?
1. RGB model
2. CMY model
3. YIQ model
4. HSI model

8. What is Hue of saturation?
Hue is a color attribute that describes a pure color where saturation gives a
measure of the degree to which a pure color is diluted by white light.
9. List the applications of color models?
1. RGB model— used for color monitor & color video camera
2. CMY model—used for color printing
3. HIS model—-used for color image processing
4. YIQ model—used for color picture transmission

10. What is Chromatic Adoption?
`  The hue of a perceived color depends on the adoption of the viewer. For example,
the American Flag will not immediately appear red, white, and blue of the viewer has
been subjected to high intensity red light before viewing the flag. The color of the flag
will appear to shift in hue toward the red component cyan.
11. Define Resolutions?
Resolution is defined as the smallest number of discernible detail in an image.
Spatial resolution is the smallest discernible detail in an image and gray level resolution
refers to the smallest discernible change is gray level.
12. What is meant by pixel?
A digital image is composed of a finite number of elements each of which has a
particular location or value. These elements are referred to as pixels or image elements or
picture elements or pels elements.

13. Define Digital image?
When x, y and the amplitude values of f all are finite discrete quantities , we call
the image digital image.

14. What are the steps involved in DIP?
1. Image Acquisition
2. Preprocessing
3. Segmentation
4. Representation and Description
5. Recognition and Interpretation

15. What is recognition and Interpretation?
Recognition means is a process that assigns a label to an object based on the
information provided by its descriptors.
Interpretation means assigning meaning to a recognized object.

16. Specify the elements of DIP system?
1. Image Acquisition
2. Storage
3. Processing
4. Display
17. Explain the categories of digital storage?
1. Short term storage for use during processing.
2. Online storage for relatively fast recall.
3. Archical  storage for infrequent access. 18. What are the types of light receptors?
The two types of light receptors are
1.  Cones and
2.  Rods
19. Differentiate photopic and scotopic vision?

Photopic vision  Scotopic vision
1. The human being can resolve
the fine details with these cones
because each one is connected to
its own nerve end.
2. This is also known as bright
light vision.
Several rods are connected to
one nerve end. So it gives the
overall picture of the image.

This is also known as thin light
vision.

20. How cones and rods are distributed in retina?
In each eye, cones are in the range 6-7 million and rods are in the range 75-150
million.