1. Define a digital image.
  2. Explain the steps involved in digital image processing (DIP).
  3. What is a geometric transformation?
  4. Obtain the digital negative of the 8-bit gray level image shown on the right.


  1. What is meant by pixel?
  2. Write short notes on neighbors of a pixel.
  3. Differentiate Median and Mean filter.
  4. Given a image shown on the right. What will the value of the center pixel change to when this image is passed through
  • Arithmetic mean filter
  • Geometric mean filter
  • Harmonic mean filter
  • Max-filter
  • Min-filter?


  • What do you mean by Color model? List the applications of color models.
  • Explain CMY color model.
  • Briefly explain how RGB color image can be converted to grayscale image.
  • With neat figures, show the histograms of four basic types of images; i.e., dark, bright, low-contrast, and high-contrast images.


  1. What is Hue and saturation?
  2. What is the difference between grayscale image and binary image?
  3. What is the number of bits required to store a image with gray levels?
  4. Given grey scale image with pixel intensities between [37..209].
    • What point operation is necessary to map the pixels to the [0..255] range?
    • What point operation is necessary to go from [0..255] back to [37..209]?
    • Do you think you will get the same image back again? Explain.


  1. The two images shown on the right are quite different, but their histograms are identical. Both images have size , with white (1) and black (0) pixels. Suppose that both images are blurred with smoothing mask.
    • Would the resultant histograms still the same?
    • Draw the two histograms and explain your answer.
  2. Given a grayscale image I, we want to find all its pixels that are in the domain [a, b]. Design a function F = func(I, a, b) that returns a binary matrix F that is of the same size as I, where 1 for pixels satisfying the domain condition and 0 otherwise.