tesseract
5.0.0-alpha-619-ge9db
otsuthr.h
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// File: otsuthr.h
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// Description: Simple Otsu thresholding for binarizing images.
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// Author: Ray Smith
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// Created: Fri Mar 07 12:14:01 PST 2008
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//
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// (C) Copyright 2008, Google Inc.
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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// http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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#ifndef TESSERACT_CCMAIN_OTSUTHR_H_
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#define TESSERACT_CCMAIN_OTSUTHR_H_
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struct
Pix;
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namespace
tesseract
{
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const
int
kHistogramSize
= 256;
// The size of a histogram of pixel values.
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// Computes the Otsu threshold(s) for the given image rectangle, making one
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// for each channel. Each channel is always one byte per pixel.
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// Returns an array of threshold values and an array of hi_values, such
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// that a pixel value >threshold[channel] is considered foreground if
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// hi_values[channel] is 0 or background if 1. A hi_value of -1 indicates
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// that there is no apparent foreground. At least one hi_value will not be -1.
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// Delete thresholds and hi_values with delete [] after use.
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// The return value is the number of channels in the input image, being
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// the size of the output thresholds and hi_values arrays.
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int
OtsuThreshold
(Pix* src_pix,
int
left,
int
top,
int
width,
int
height,
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int
** thresholds,
int
** hi_values);
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// Computes the histogram for the given image rectangle, and the given
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// single channel. Each channel is always one byte per pixel.
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// Histogram is always a kHistogramSize(256) element array to count
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// occurrences of each pixel value.
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void
HistogramRect
(Pix* src_pix,
int
channel,
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int
left,
int
top,
int
width,
int
height,
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int
* histogram);
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// Computes the Otsu threshold(s) for the given histogram.
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// Also returns H = total count in histogram, and
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// omega0 = count of histogram below threshold.
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int
OtsuStats
(
const
int
* histogram,
int
* H_out,
int
* omega0_out);
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}
// namespace tesseract.
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#endif // TESSERACT_CCMAIN_OTSUTHR_H_
tesseract::OtsuStats
int OtsuStats(const int *histogram, int *H_out, int *omega0_out)
Definition:
otsuthr.cpp:187
tesseract::kHistogramSize
const int kHistogramSize
Definition:
otsuthr.h:27
tesseract
Definition:
baseapi.h:65
tesseract::HistogramRect
void HistogramRect(Pix *src_pix, int channel, int left, int top, int width, int height, int *histogram)
Definition:
otsuthr.cpp:166
tesseract::OtsuThreshold
int OtsuThreshold(Pix *src_pix, int left, int top, int width, int height, int **thresholds, int **hi_values)
Definition:
otsuthr.cpp:56
src
ccstruct
otsuthr.h
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