Question

The two steps: one is the creation of new pixel locations, and other is the assignment of gray levels to those new locations are involved in ____________

(a) Shrinking

(b) Zooming

(c) All of the mentioned

(d) None of the mentioned

The question was asked in quiz.

Question is taken from Zooming and Shrinking Digital Images in section Image Enhancement of Digital Image Processing

Answer 1

The correct option is (b) Zooming

The explanation is: Suppose that we have an image of size500*500pixels and we want to enlarge it 1.5 times to 750*750pixels.

Creation of new Pixels: One of the easiest ways to visualize zooming is laying an imaginary 750*750 grid over the original image and so there would be less spacing by one pixel in the grid because we are fitting it over a smaller image.

Assignment of gray levels to new locations: In order to perform gray-level assignment for any point in the overlay, we assign its gray level to the new pixel in the grid its closest pixel in the original image.

When the above steps are done with all points in the overlay grid, we expand it to the original specified size to obtain the zoomed image.