| 摘要 |
The present invention relates to digital image processing and can be used to solve problems concerning processing of digital images obtained with the use of high-energy radiation including the X-rays. The present invention relates in particular to noise assessment of digital X-ray films. A method of digital X-ray film noise assessment includes acquisition of an original image; low-frequency filtering of the original image to obtain an estimated images; by means of morphologic filtering elimination of noise image pixels corresponding to sharp changes in the original image; division of intensity range of the estimated image into intervals, herewith each pixel of the estimated image relates to an appropriate interval; accumulating for each interval some noise image pixels corresponding to estimated image pixels; calculating interval estimations of noise dispersion using accumulated in such an interval noise image pixels; improving interval estimations by the use of removal noise pixels according to &sgr; 3 criteria, robust local linear approximation of interval estimations of noise dispersion, that results in tabular function describing the dependence of noise on signal intensity; calculation on the base of estimated image and obtained tabular function of the dependence of noise on signal intensity the noise map as a pixel-by-pixel noise dispersion estimation of the digital original image. The technical result is the higher rate and quality of the digital X-ray film noise estimation. |
