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Computer Vision with Python 3 by Saurabh Kapur

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Scale-space extrema detection

In the first stage of SIFT, we aim to achieve scale invariance by generating a multiple scale pyramid of the original image as shown in Figure 3:

Figure 3: Original image blurred and resized to generate four octaves

What we are essentially doing here is getting rid of details that do not persist at different scales. By doing so, we are only left with information that is scale invariant. Now, to achieve the pyramid shown in the preceding figure, we apply Gaussian Blur to the image.

We first take the original image and apply Gaussian Blur five times with different sigma values. This results in five blurred images ...

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