Colour Vignetting Correction for Microscopy Image Mosaics Used for Quantitative Analyses

Figure 3

Saturated pixels. (a) Let us consider the blue continuous curve as a representative of the intensity profile of the blue line in the image reported in the top-right corner. Considering the image as directly proportional to the vignetting function, the black continuous line represents the intensity profile after correcting vignetting according to (1). (b) All the saturated pixels (represented as a blue dotted segment), pixels with intensity value higher than 255 (red dashed line), are captured at 255, thus losing the connection with the original radiance. The same happens for the green continuous curve achieved after normalizing the new blue continuous curve with the vignetting function. (c) In the proposed vignetting correction approach, all pixels that before normalization were at 255 are set back to 255.

(a)

(b)

(c)