Compensating MTF measurements for chart quality limitations by Norman Koren #EI2019

Objective measurements of imaging system sharpness are typically derived from test chart images. It is generally assumed that if testing instructions are followed—if the chart print quality is fine enough and the chart magnification (on the sensor) is low enough— test chart quality will have little impact on the overall measurement.

This assumption may not be valid when extremely high-resolution cameras are tested with standard charts or when smaller than optimum test charts are used because of laboratory or production line space limitations.

MTF compensation is applied by dividing the measured system MTF by chart-projected MTF as a function of the sensor.
Measurements made under different conditions— with different test charts (transmissive as well as reflective) by different people in different labs— are more consistent.
The megapixel suitability of test charts is increased by a factor of approximately 2 (1.4x linearly).
The key advantage of MTF compensation is that measurements are more accurate (in an absolute sense).

Видео Compensating MTF measurements for chart quality limitations by Norman Koren #EI2019 канала Imatest LLC