Last modified: November 20, 2009
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Image [OneBit] abutaleb_threshold (Choice [dense|rle] storage format)
Operates on: | Image [GreyScale] |
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Returns: | Image [OneBit] |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Michael Droettboom and Karl MacMillan |
Creates a binary image by using the Abutaleb locally-adaptive thresholding algorithm.
specifies the compression type for the result:
Example 1: abutaleb_threshold()
Image [OneBit] bernsen_threshold (Choice [dense|rle] storage format, int(1, 50) region size = 20, int(0, 255) contrast limit = 5, bool doubt)
Operates on: | Image [GreyScale] |
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Returns: | Image [OneBit] |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Michael Droettboom and Karl MacMillan |
Creates a binary image by using the Bernsen algorithm.
specifies the compression type for the result:
Example 1: bernsen_threshold()
Image [OneBit] djvu_threshold (float(0.00, 1.00) smoothness = 0.20, int max_block_size = 512, int min_block_size = 64, int(1, 8) block_factor = 2)
Operates on: | Image [RGB] |
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Returns: | Image [OneBit] |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Michael Droettboom and Karl MacMillan |
Creates a binary image by using the DjVu thresholding algorithm.
See Section 5.1 in:
Bottou, L., P. Haffner, P. G. Howard, P. Simard, Y. Bengio and Y. LeCun. 1998. High Quality Document Image Compression with DjVu. AT&T Labs, Lincroft, NJ.
This implementation features an additional extension to the algorithm described above. Once the background and foreground colors are determined for each block, the image is thresholded by interpolating the foreground and background colors between the blocks. This prevents "blockiness" along boundaries of strong color change.
Example 1: djvu_threshold(0.5, 512, 64, 2)
int otsu_find_threshold ()
Operates on: | Image [GreyScale] |
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Returns: | int |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Michael Droettboom and Karl MacMillan |
Finds a threshold point using the Otsu algorithm. Reference:
N. Otsu: A Threshold Selection Method from Grey-Level Histograms. IEEE Transactions on Systems, Man, and Cybernetics (9), pp. 62-66 (1979)
Example 1: otsu_find_threshold()
result = 143
Image [OneBit] otsu_threshold (Choice [dense|rle] storage format)
Operates on: | Image [GreyScale] |
---|---|
Returns: | Image [OneBit] |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Michael Droettboom and Karl MacMillan |
Creates a binary image by splitting along a threshold value determined using the Otsu algorithm.
Equivalent to image.threshold(image.otsu_find_threshold()).
specifies the compression type for the result:
Example 1: otsu_threshold()
Image [OneBit] threshold (int threshold, Choice [dense|rle] storage format)
Operates on: | Image [GreyScale|Grey16|Float] |
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Returns: | Image [OneBit] |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Michael Droettboom and Karl MacMillan |
Creates a binary image by splitting along a given threshold value.
Pixels that are greater than the given value become white. Pixels less than the given value become black.
specifies the compression type for the result:
Example 1: threshold(128)
int tsai_moment_preserving_find_threshold ()
Operates on: | Image [GreyScale] |
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Returns: | int |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Uma Kompella |
Finds a threshold point using the Tsai Moment Preserving threshold algorithm. Reference:
W.H. Tsai: Moment-Preserving Thresholding: A New Approach. Computer Vision Graphics and Image Processing (29), pp. 377-393 (1985)
Example 1: tsai_moment_preserving_find_threshold()
result = 153
Image [OneBit] tsai_moment_preserving_threshold (Choice [dense|rle] storage format)
Operates on: | Image [GreyScale] |
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Returns: | Image [OneBit] |
Category: | Thresholding |
Defined in: | threshold.py |
Author: | Uma Kompella |
Creates a binary image by splitting along a threshold value determined using the Tsai Moment Preserving Threshold algorithm.
Equivalent to image.threshold(image.tsai_moment_preserving_find_threshold()).
specifies the compression type for the result:
Example 1: tsai_moment_preserving_threshold()