Fig. 4

Simulation results for the cell cluster dataset. Errors (mean ± standard deviation) between estimated and actual values for each parameter using images of the cell cluster dataset (N = 1000). The errors are shown for images blurred with Gaussian kernels having standard deviations from 0 to 5 pixels (a), images with additive white Gaussian noise having normalized variances from 0 to 2.5 % (b) and images with Poisson distributed noise at levels 0–20 (c). For the mean orientation, the errors are absolute and given in degrees. For the other parameters, the errors were normalized by the range of true values. Examples of images with moderate blurring (std 2.5 pixels) (d), Gaussian noise (var. 1 %) (e) and Poisson noise (level 10) (f) are shown