METHOD AND DEVICE FOR REMOVING IMAGE NOISE BASED ON THE MEDIAN FILTER

摘要

A method and device for removing the noise of image on the basis of the median filter are disclosed, the method and device are used for removing the linear noise and random noise of the sensor, removing the bad point of the sensor image and preventing excessive noise removal are disclosed. The technical scheme is that: the method includes: for the current point cur_pixel, obtaining three combinations from the ambient pixel points, calculating the median values F1, F2 and F3 of every combinations; calculating the reference luminance value Y: Y=F2+[F1+F3-2*F2]*h*[1-k*var], with var=F3-F1; determining whether cur_pixel is a bad point, if it is a bad point, letting tmp_data=F1, else letting tmp_data=cur_pixel; determining whether the current point is a point in the edge portion, if it is a point in the edge portion, thus limiting Y to [tmp_data-edge_limit, tmp_data+edge_limit], and updating cur_pixel, thus the noise removal being finished; if it is not a point in the edge portion, then further determining that the value of |Y-tmp_data| is less than the value of avoid_over_noise or not, if |Y-tmp_data|