Correction method of imaging luminance measurement device

The imaging luminance measurement device (ILMD) can utilize the image sensor and the short focal length lens to achieve a large field of view and spatially resolved luminance measurement. However, there still exists problems of pixel nonlinear response of image sensor, strong vignetting effects of short focal length lens and image distortion. Therefore, a correction method of ILMD was proposed. Linear correction and flat-field correction were used to obtain linear correction coefficients and flat-field correction matrices by using standard radiation source method. The distortion correction matrix was obtained through the geometric coordinates calibration method. A 12 mm short focal length lens and a 2-megapixel image sensor were adopted to build an ILMD. After correction, the luminance measurement of the LCD panel was completed. It was compared with a commercial spectroradiometer and the test results show that the relative error of measurement does not exceed ±2%, which realizes the large field of view, high-precision and spatially resolved luminance measurement.