The maximum gradient and the
average gradient of the image are defined as:
where [Ave.sub.v], [Ave.sub.H] are
average gradients in vertical and horizontal direction, respectively and AG is the
average gradient of the fused image F.
Where Dg (fJ) means the gradient distribution of the estimate image of fJ, and the average Dg means the
average gradient distribution of database face images which is shown in Fig.
As a result, considering the edge information of the source image, the region
average gradient is selected as the linking strength to improve its self-adaptability in this paper.
Maximizing
average gradient [G.sub.A] obtains more accurate contour and avoids oversegmentation.
Various metrics such as Qabf, VIF, Mutual Information,
Average Gradient and Entropy are used to measure the image quality.
The
average gradient can sensitively reflect the capability of a digital image contrast expression of tiny details and texture transformation characteristics, is used to evaluate the image blur degree.
The
average gradient is about 24 percent and the "unofficial'' list cites a steepest grade of 30 percent.
The hardest was the 4.7-kilometer Holme Moss pass, and the steepest was also the shortest: The 800-meter Jenkin Road pass, with an
average gradient of 10.8 percent -- just 5 kilometers from the finish line.
The slope gradient of each pixel is calculated based on DEM data and the
average gradient threshold values of gully thalweg and gully edge line were measured in field.
First there was a 221km ride south from Givors just to get to Mont Ventoux, before the 21.5km ascent of 'God's Tomb', at an
average gradient of 7.5% to the summit 1,912 metres above sea level.
With a 10 per cent
average gradient and some pitches at 16 per cent, the day's final climb was labelled "steeper than Alpe d'Huez", according to race organiser, Belgian legend Eddy Merckx, in reference to the legendary alpine ascension.
