HOGOperation

java.lang.Object
- com.emphysic.myriad.core.data.ops.HOGOperation

All Implemented Interfaces:

DatasetOperation, ObjectMap, com.esotericsoftware.kryo.KryoSerializable
```
public class HOGOperation
extends java.lang.Object
implements DatasetOperation
```
HOGOperation - an implementation of the Histogram of Oriented Gradients (HOG) algorithm as outlined in Dalal, Navneet, and Bill Triggs. "Histograms of oriented gradients for human detection." 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05). Vol. 1. IEEE, 2005. Based in part on the Chris McCormick MATLAB implementation discussed at http://mccormickml.com/2013/05/09/hog-person-detector-tutorial/ . Created by chris on 8/5/2016.

Constructor Summary

Constructors
Constructor and Description
`HOGOperation()` Construct a HOG operation with a cell radius of 4, 4 cells per block, and 9 histogram bins.
`HOGOperation(int cellRadius, int blockSize, int nbins)` Construct a HOG operation.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Dataset`	`descriptors(Dataset input)` Computes the normalized HOG descriptors for the specified input
`int`	`getBlockSize()` Number of cells in a block in one dimension i.e.
`int`	`getCellRadius()` Number of data points in a cell's radius.
`int`	`getCellWidth()` Total width of a square cell
`double`	`getMAXANGLE()` Maximum angle in the histogram in radians.
`double`	`getMINANGLE()` Minimum angle in the histogram in radians.
`int`	`getNbins()` Number of bins in the local histgram
`java.util.Map<java.lang.String,java.lang.Object>`	`getObjectMap()` Creates a map of the important fields for the instance, suitable for serialization.
`long`	`getSerializationVersion()` Returns the current version of the serialization format.
`int`	`getVersion()` Returns the current class version.
`GradientVector`	`gradientVector(Dataset input)` Calculates the gradient vector of the input
`void`	`initCurrentVersion(java.util.Map<java.lang.String,java.lang.Object> objectMap)` Initializes an instance with a current-version object graph.
`static void`	`main(java.lang.String[] args)`
`double[]`	`normalize(double[] data)` Normalizes an array by dividing each element by the magnitude of the vector.
`Dataset`	`run(Dataset input)` Runs the operation on an input.
`void`	`setBlockSize(int blockSize)`
`void`	`setCellRadius(int cellRadius)`
`void`	`setCellWidth(int cellWidth)`
`void`	`setMAXANGLE(double MAXANGLE)` Sets the maximum angle in the histogram in radians.
`void`	`setMINANGLE(double MINANGLE)` Sets the minimum angle in the histogram in radians.
`void`	`setNbins(int nbins)` Sets the number of bins to use in the histogram

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.emphysic.myriad.core.data.util.ObjectMap
init, initPreviousVersion, initUnknownVersion, load, read, save, write

- Constructor Detail
  - HOGOperation
```
public HOGOperation()
```
    Construct a HOG operation with a cell radius of 4, 4 cells per block, and 9 histogram bins. Each cell contains (2*4+1)^2 = 81 pixels, 324 pixels per block, and the final descriptor vector is [number of blocks in input] * 9 elements.
  - HOGOperation
```
public HOGOperation(int cellRadius,
                    int blockSize,
                    int nbins)
```
    Construct a HOG operation.
    
    Parameters:
    
    cellRadius - radius of a cell (number of points in one cell = (2*r + 1)^2)
    
    blockSize - radius of a block (number of cells in one block = bs * bs)
    
    nbins - number of histogram bins
- Method Detail
  - run
```
public Dataset run(Dataset input)
```
    Description copied from interface: DatasetOperation
    
    Runs the operation on an input.
    
    Specified by:
    
    run in interface DatasetOperation
    
    Parameters:
    
    input - Dataset on which to operate
    
    Returns:
    
    result
  - gradientVector
```
public GradientVector gradientVector(Dataset input)
```
    Calculates the gradient vector of the input
    
    Parameters:
    
    input - input Dataset
    
    Returns:
    
    gradient vector
  - descriptors
```
public Dataset descriptors(Dataset input)
```
    Computes the normalized HOG descriptors for the specified input
    
    Parameters:
    
    input - data to inspect
    
    Returns:
    
    a descriptor Dataset of size (number of blocks * number of bins * number of cells / block) X 1, or null if no data
  - normalize
```
public double[] normalize(double[] data)
```
    Normalizes an array by dividing each element by the magnitude of the vector.
    
    Parameters:
    
    data - data to normalize
    
    Returns:
    
    normalized data
  - getCellRadius
```
public int getCellRadius()
```
    Number of data points in a cell's radius.
    
    Returns:
    
    cell's radius in data points.
  - setCellRadius
```
public void setCellRadius(int cellRadius)
```
  - getCellWidth
```
public int getCellWidth()
```
    Total width of a square cell
    
    Returns:
    
    cell's width i.e. 2 * cellRadius + 1
  - setCellWidth
```
public void setCellWidth(int cellWidth)
```
  - getBlockSize
```
public int getBlockSize()
```
    Number of cells in a block in one dimension i.e. total cells = blockSize * blockSize
    
    Returns:
    
    number of cells per block
  - setBlockSize
```
public void setBlockSize(int blockSize)
```
  - getNbins
```
public int getNbins()
```
    Number of bins in the local histgram
    
    Returns:
    
    number of bins
  - setNbins
```
public void setNbins(int nbins)
```
    Sets the number of bins to use in the histogram
    
    Parameters:
    
    nbins - number of bins
  - getMAXANGLE
```
public double getMAXANGLE()
```
    Maximum angle in the histogram in radians. Original paper used PI.
    
    Returns:
    
    maximum angle in radians
  - setMAXANGLE
```
public void setMAXANGLE(double MAXANGLE)
```
    Sets the maximum angle in the histogram in radians. Original paper used PI.
    
    Parameters:
    
    MAXANGLE - maximum angle in radians
  - getMINANGLE
```
public double getMINANGLE()
```
    Minimum angle in the histogram in radians. Original paper used 0.
    
    Returns:
    
    minimum angle in radians
  - setMINANGLE
```
public void setMINANGLE(double MINANGLE)
```
    Sets the minimum angle in the histogram in radians. Original paper used 0.
    
    Parameters:
    
    MINANGLE - minimum angle in radians
  - getSerializationVersion
```
public long getSerializationVersion()
```
    Description copied from interface: ObjectMap
    
    Returns the current version of the serialization format. Increments when the serialization format changes, i.e. backwards compatibility is broken.
    
    Specified by:
    
    getSerializationVersion in interface ObjectMap
    
    Returns:
    
    serialization version
  - getVersion
```
public int getVersion()
```
    Description copied from interface: ObjectMap
    
    Returns the current class version. Class version increments when the class changes but doesn't necessarily break compatibility with serialization.
    
    Specified by:
    
    getVersion in interface ObjectMap
    
    Returns:
    
    class version
  - getObjectMap
```
public java.util.Map<java.lang.String,java.lang.Object> getObjectMap()
```
    Description copied from interface: ObjectMap
    
    Creates a map of the important fields for the instance, suitable for serialization.
    
    Specified by:
    
    getObjectMap in interface ObjectMap
    
    Returns:
    
    "object map" of the instance
  - initCurrentVersion
```
public void initCurrentVersion(java.util.Map<java.lang.String,java.lang.Object> objectMap)
```
    Description copied from interface: ObjectMap
    
    Initializes an instance with a current-version object graph.
    
    Specified by:
    
    initCurrentVersion in interface ObjectMap
    
    Parameters:
    
    objectMap - object graph for initialization
  - main
```
public static void main(java.lang.String[] args)
                 throws java.lang.Exception
```
    Throws:
    
    java.lang.Exception

Class HOGOperation

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.emphysic.myriad.core.data.util.ObjectMap

Constructor Detail

HOGOperation

HOGOperation

Method Detail

run

gradientVector

descriptors

normalize

getCellRadius

setCellRadius

getCellWidth

setCellWidth

getBlockSize

setBlockSize

getNbins

setNbins

getMAXANGLE

setMAXANGLE

getMINANGLE

setMINANGLE

getSerializationVersion

getVersion

getObjectMap

initCurrentVersion

main