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Fractal Software => Others => Topic started by: dommy on March 31, 2013, 01:10:15 PM




Title: Fractal Dimension for 2d images
Post by: dommy on March 31, 2013, 01:10:15 PM
Hi all,

I am new to this topic so pls bear with me whilst i catch up with everyone else.

I have 2 images of the same tree/bush blowing in the wind. I take the difference of these 2 images and a distinctive/repeating pattern emerges. I would like to know if it is possible to calculate the fractal dimension of this image. The goal is to determine whether motion caught between 2 images is a tree/bush blowing in the wind or something else based on the fractal dimension value.

I am using C#.

Any suggestions or pointer would be great.

thanks


Title: Re: Fractal Dimension for 2d images
Post by: cKleinhuis on March 31, 2013, 01:40:08 PM
hi there, and welcome to the forums

fractal dimension calculation can be easy or complex ;)

but for a first starter, the bigger the image the better you are, the fractal dimension might be first calculated using the boxcounting dimension,
this is a rather simple task, you take a black and white image and then you decrease the box sizes and count for each box size  ho many
boxes overlap with your image, the dimension is then obtained by applying a loglog or closed fitting line through the obtained results
the idea is that a box of side length 1x1 has 1 square and the halved box length of 0.5 would fit 4 times into the original 1x1 box
i struggled with it as well and the results for images can be rather unsharp or exhibit massive changes due to just 1 pixel shift or something

there is a program called imagej which might be able to do the same thing as well:
http://en.wikipedia.org/wiki/ImageJ


Title: Re: Fractal Dimension for 2d images
Post by: dommy on March 31, 2013, 01:42:47 PM
hi,

Thank you so much or you reply. Especially on Easter!

The image dimension is 352x288.

I shall take a look at that link.

Best...