My porblem understanding Local Binary Pattern

[ginger wend]

Hi,

I am trying to learn Local Binary Pattern with scikit-image and as I have only limited knowledge in numpy and image analysis I find it hard. As a result, I will appreciate a lot if you can provide me some answers as I am sure that they will help me to advance:

- If I understand correctly the skimage.feature.local_binary_pattern(image, P, R, method=' uniform) will go pixel by pixel (starting from pixel location 1,2) and generate the binary number based on the P and R, am I right?. If so what happens if the R is “out of boundary”?
- How do you calculate the histogram and why are there are 18 bins in the example (http://scikit-image.org/docs/dev/auto_examples/plot_local_binary_pattern.html)?
- The output is (N, M) array and when I look at it is not clear to me what is the output and how do you generate a histogram from it, can someone you please clarify it.

I know that these questions are be basic and while I was trying to look for answers I found the information more mathematical and less with applied approach. Therefore, any help, ideas or tips will help.

Thanks for the patience,
G.

[Tony Yu]

Hi,

LBP can be quite confusing at first, but the idea is pretty simple. I recently added some more explanations to the example in the gallery (most of the addition is code to plot things---you don't really need to understand that part of the code):

https://github.com/scikit-image/scikit-image/blob/master/doc/examples/plot_local_binary_pattern.py

That example should clarify most of your questions. I don't really know how the boundary is treated, so maybe someone else can clarify that point.

Best,

-Tony

[Johannes Schönberger]

The image is padded with 0s.

Johannes Schönberger

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[ginger wend]

Does it work with also with scikit-image 0.8 or only with 0.9dev?

Im using 0.8 and got some error regrarding label2rgb.

[Johannes Schönberger]

I think, label2rgb was added in 0.9dev and thus is not available in 0.8.

Johannes Schönberger

[ginger wend]

How can I intall 0.9dev on windows?

[Tony Yu]

On Sat, Jul 13, 2013 at 6:48 AM, ginger wend <gin...@walla.com> wrote:

How can I intall 0.9dev on windows?

Hi, there are instructions on the website:

http://scikit-image.org/docs/dev/install.html#installation-from-source

Alternatively, I've attached a version of the example that drops the dependency on label2rgb. Another alternative would be for us to update the docs displayed on the website, but I can't ever remember how to do that. :P

Cheers,

-Tony