Enter the contrast in the image and the contrast in the target into the Calculator. The calculator will evaluate the Modulation Transfer Function. 

Modulation Transfer Function Formula

MTF = CI / CT

Variables:

  • MTF is the Modulation Transfer Function ()
  • CI is the contrast in the image
  • CT is the contrast in the target

To calculate the Modulation Transfer Function, divide the contrast in the image by the contrast in the target.

How to Calculate Modulation Transfer Function?

The following steps outline how to calculate the Modulation Transfer Function.

  • First, determine the contrast in the image. 
  • Next, determine the contrast in the target. 
  • Next, gather the formula from above = MTF = CI / CT.
  • Finally, calculate the Modulation Transfer Function.
  • After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

contrast in the image = 1.78

contrast in the target = 2.94

FAQs about Modulation Transfer Function

What is the importance of Modulation Transfer Function (MTF) in imaging systems?

MTF is crucial in imaging systems as it quantifies the system’s ability to reproduce (or transfer) detail from the object to the image. It essentially measures the image quality, indicating how well a system can preserve the contrast and details of the original object.

How does contrast affect the Modulation Transfer Function?

Contrast plays a significant role in MTF since the formula involves the contrast in the image and the contrast in the target. Higher contrast in the image relative to the target indicates a higher MTF, meaning the system can better transfer details. Conversely, lower contrast results in a lower MTF, indicating a loss in detail and potentially lower image quality.

Can the Modulation Transfer Function be greater than 1?

Typically, MTF values range from 0 to 1, where 1 represents perfect detail transfer without any loss. An MTF greater than 1 is unusual and might indicate an amplification in contrast rather than an accurate representation of the target’s detail. However, this is generally not expected in standard imaging systems.

Are there any limitations to using MTF for assessing image quality?

While MTF is a valuable metric for assessing the spatial resolution and contrast detail of imaging systems, it does not account for all aspects of image quality, such as color accuracy, dynamic range, and noise. Therefore, it is often used in conjunction with other metrics to provide a comprehensive evaluation of an imaging system’s performance.