Package boofcv.alg.filter.binary

Class ThresholdBlockOtsu

java.lang.Object

boofcv.alg.filter.binary.ThresholdBlockOtsu

All Implemented Interfaces:

ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>

public class ThresholdBlockOtsu
extends Object
implements ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>

Block Otsu threshold implementation based on ThresholdBlock. Computes a histogram in non-overlapping square regions. Then thresholds a single region by combining histograms from its neighbors to make it less blocky. This implementation includes a modification from the traditional Otsu algorithm. The threshold can optionally be adjusted in low variance regions. See code for details.

NOTE: This produces visually different results from ThresholdBlockOtsu because the block algorithm combines histograms from its neighboring blocks. That's why it appears to have a wider effective block.

See Also:

• GThresholdImageOps.computeOtsu(ImageGray, double, double)

Field Summary

Fields

Modifier and Type	Field	Description
protected int	blockHeight
protected int	blockWidth
protected boolean	thresholdFromLocalBlocks

Constructor Summary

Constructors

Constructor	Description
ThresholdBlockOtsu(boolean otsu2, double tuning, double scale, boolean down)	Configures the detector

Method Summary

Modifier and Type	Method	Description
void	computeBlockStatistics(int x0, int y0, int width, int height, int indexStats, GrayU8 input, InterleavedS32 stats)	Computes the min-max value inside a block
ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>	copy()	Creates a copy.
InterleavedS32	createStats()
void	init(int blockWidth, int blockHeight, boolean thresholdFromLocalBlocks)
void	thresholdBlock(int blockX0, int blockY0, GrayU8 input, InterleavedS32 stats, GrayU8 output)	Thresholds all the pixels inside the specified block

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

blockWidth

protected int blockWidth

blockHeight

protected int blockHeight

thresholdFromLocalBlocks

protected boolean thresholdFromLocalBlocks

Constructor Details

ThresholdBlockOtsu

public ThresholdBlockOtsu(boolean otsu2,
 double tuning,
 double scale,
 boolean down)

Configures the detector

Parameters:

tuning - Tuning parameter. 0 = standard Otsu. Greater than 0 will penalize zero texture.

Method Details

createStats

public InterleavedS32 createStats()

Specified by:

createStats in interface ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>

init

public void init(int blockWidth,
 int blockHeight,
 boolean thresholdFromLocalBlocks)

Specified by:

init in interface ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>

computeBlockStatistics

public void computeBlockStatistics(int x0,
 int y0,
 int width,
 int height,
 int indexStats,
 GrayU8 input,
 InterleavedS32 stats)

Description copied from interface: ThresholdBlock.BlockProcessor

Computes the min-max value inside a block

Specified by:

computeBlockStatistics in interface ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>

Parameters:

x0 - lower bound pixel value of block, x-axis

y0 - upper bound pixel value of block, y-axis

width - Block's width

height - Block's height

indexStats - array index of statistics image pixel

input - Input image

thresholdBlock

public void thresholdBlock(int blockX0,
 int blockY0,
 GrayU8 input,
 InterleavedS32 stats,
 GrayU8 output)

Description copied from interface: ThresholdBlock.BlockProcessor

Thresholds all the pixels inside the specified block

Specified by:

thresholdBlock in interface ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>

Parameters:

blockX0 - Block x-coordinate

blockY0 - Block y-coordinate

input - Input image

output - Output image

copy

public ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32> copy()

Description copied from interface: ThresholdBlock.BlockProcessor

Creates a copy. For concurrent code

Specified by:

copy in interface ThresholdBlock.BlockProcessor<GrayU8,InterleavedS32>