Test on Digital Image Enhancement and Noise Suppression

Question 1: If the gamma parameter is greater than 1 (𝛾 > 1), the gamma contrast transformation results in a brighter image.

A. Ano

B. Ne

Explanation: The study materials indicate that when the gamma parameter 𝛾 > 1, the gamma contrast transformation makes the image darker, not brighter.

Question 2: According to the study materials, what do the 'W' (Width) and 'L' (Level) parameters of a radiological window represent?

A. W represents the range width with increasing dynamics, and L represents the shift of the window center.

B. W adjusts the overall image brightness, while L determines the image's bit depth.

C. W is the minimum intensity threshold, and L is the maximum intensity threshold for the window.

D. Both W and L are used to define the exponents in gamma contrast transformation.

Explanation: The study materials state that 'W' (Width of window) defines the 'range width with increasing dynamics', and 'L' (Level of window) defines the 'shift of window center'.

Question 3: Adaptive image sharpening can be controlled by a gradient image.

A. Ano

B. Ne

Explanation: Adaptive image sharpening can be controlled by a specific function, and the gradient image is given as an example of such a control function for approaches via an anisoplanar operator.

Question 4: According to the study materials, which statements accurately describe adaptive image sharpening using an anisoplanar operator?

A. It is controlled by a specific function that can be either binary or continuous.

B. Its primary application is to enhance regions with homogenous intensity.

C. An example of its binary controlled implementation combines images based on gradient magnitude.

D. It exclusively uses wavelet transformation for its operation.

Explanation: Adaptive image sharpening via an anisoplanar operator is controlled by a specific function, which can be binary or continuous, making the first statement correct. An example implementation for binary controlled sharpening using an anisoplanar operator involves the combination of images by the values of gradient magnitude, validating the third statement. Sharpening is used at the location of edges only, not primarily to enhance homogenous intensity regions, which refutes the second statement. The study materials list wavelet transformation as a separate approach to adaptive image sharpening, not an exclusive part of the anisoplanar operator method, making the fourth statement incorrect.

Question 5: The Sobel operator does not function as a special noise-resistant gradient operator.

A. Ano

B. Ne

Explanation: The study materials explicitly state that Sobel’s operator is a 'special noise-resistant gradient operator'.