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Switched to using integrate Cython function from skimage._shared. All changes were made to make it fit.
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@@ -3,36 +3,33 @@
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Multi-Block Local Binary Pattern for texture classification
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===========================================================
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In this example, we will see how to compute the multi-block
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local binary pattern at a specified image and how to visualize it.
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This example shows how to compute multi-block local binary
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pattern (MB-LBP) features as well as how to visualize them.
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The features are calculated in a way similar to local binary
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patterns, except that summed up pixel values
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rather than pixel values are used.
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The features are calculated similarly to local binary patterns (LBPs),
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except that summed blocks are used instead of individual pixel values.
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`MB-LBP` is an extension of LBP that can be computed on any
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scale in a constant time using integral image. It consists of
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`9` equal-sized rectangles. They are used to compute a feature.
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Sum of pixels' intensity values in each of them are compared
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to the central rectangle and depending on comparison result,
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the feature descriptor is computed.
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MB-LBP is an extension of LBP that can be computed on multiple scales
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in constant time using the integral image.
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9 equally-sized rectangles are used to compute a feature.
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For each rectangle, the sum of the pixel intensities is computed.
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Comparisons of these sums to that of the central rectangle determine
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the feature, similarly to LBP (See `LBP <plot_local_binary_pattern.html>`_).
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We will start with a simple image that we will generate
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to show how the `MB-LBP` works. We will create a `(9, 9)`
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rectangle with and divide it into `9` blocks. After this
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we will apply `MB-LBP` on it.
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First, we generate an image to illustrate the functioning of MB-LBP:
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we take a (9, 9) rectangle and divide it into (3, 3) block,
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upon which we then apply MB-LBP.
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"""
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from __future__ import print_function
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from skimage.feature import multiblock_local_binary_pattern
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import numpy as np
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from skimage.util import img_as_float
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from skimage.transform import integral_image
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# Create dummy matrix where first and fifth
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# rectangles have greater value than the central one
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# Therefore, the following bits should be 1.
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# Create test matrix where first and fifth
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# rectangles starting from top left clockwise
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# have greater value than the central one.
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test_img = np.zeros((9, 9), dtype='uint8')
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test_img[3:6, 3:6] = 1
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test_img[:3, :3] = 50
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@@ -43,14 +40,12 @@ test_img[6:, 6:] = 50
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# be filled.
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correct_answer = 0b10001000
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# The function accepts the float images.
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# Also it has to be C-contiguous.
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test_img = img_as_float(test_img)
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int_img = integral_image(test_img)
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lbp_code = multiblock_local_binary_pattern(int_img, 0, 0, 3, 3)
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print(lbp_code == correct_answer)
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print(correct_answer)
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print(lbp_code)
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"""
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Now let's apply the operator to a real image and see how the visualization works.
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@@ -61,7 +56,6 @@ from skimage.feature import draw_multiblock_lbp
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test_img = data.coins()
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test_img = img_as_float(test_img)
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int_img = integral_image(test_img)
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lbp_code = multiblock_local_binary_pattern(int_img, 0, 0, 90, 90)
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@@ -75,8 +69,8 @@ plt.imshow(img, interpolation='nearest')
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"""
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.. image:: PLOT2RST.current_figure
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On the above plot we see the result of computing a `MB-LBP` and visualization
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On the above plot we see the result of computing a MB-LBP and visualization
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of the computed feature. The rectangles that have less intensity than the central
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rectangle are marked with cyan color. The ones that have bigger intensity values
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are marked with white color. The central rectangle is left untouched.
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rectangle are marked in cyan. The ones that have bigger intensity values
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are marked in white. The central rectangle is left untouched.
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"""
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