Fractal-based texture analysis

Fractal geometry was applied in the modelling of nature texture exhibited in a digital image. One important parameter that can be derived and then used for texture characterization is the fractal dimension, which can be determined using two separate methods. In the first method, the fractal dimension is estimated based on the average intensity difference of the pixels within the region of interest. In the second method, the fractal dimension is determined from the Fourier power spectrum of the image data. In order to assess the effectiveness of the fractal dimension, the regions of interest were also analyzed using spatial grey level matrices statistics. Fractal dimension seems to be good in describing many natural textures as well as many human tissues as displayed in medical images such as the ultrasonic image. The results also show that the fractal dimension is a better parameter than many second-order statistics in texture characterization. The possible reasons are that many natural textures are very similar to fractal surfaces, and also the way the fractal model describing surface roughness correlates closely to human perception of texture