DLSignatureDetect.h File Reference

#include "DLImage.h"
#include "getLines.h"
#include "DLConnectedComponents.h"
#include "DLBitsPerPixelConverter.h"
#include "DLZone.h"
#include "DLConst.h"
#include "DLLogger.h"
#include <list>

Go to the source code of this file.

Classes

struct  DLSignatureCandidate
 struct for storing a signature candidate and its associated information More...
class  DLSignatureDetect
 DLSignatureDetectDOCLIB implements a multi-scale signature detection and segmentation approach. The detection algorithm works in one of the two modes specified by the user. It can either detect signatures by looking at the entire document image, or detect signatures by exploring document context. When using document context, it effectively estimate statistics of machine printed text lines and use them to locate the region below the main body of the document text, where signatures typically appear. Using document context is more effective for machine printed documents. More...
struct  DLSignatureDetect::DLSignatureDetectParameters
 struct for storing the language and dataset dependent parameters for signature detection

Defines

#define RESIZE_FILTER_WIDTH   3.0
 The support size of the image resize filter.
#define EDGE_MAG_THRE   50
 The threshold value for the edge intensity image.
#define MIN_ORIENTATION_DIFF   8
 The step value for a change in the edge orientation image.
#define MAX_SIG_SPACING   37
 The max space between parts of signatures during contour grouping.
#define MAX_SIG_HEIGHT   600
 The max height of signature at the initial coarse image scale.
#define MAX_DATARUN_LENGTH   50
 The length of the largest connected strip in the same line (either horizontal or vertical).
#define LAMBDA_UPPER   10.0
 This upper limit in the lambda value avoids the discrete effect when using estimated edge gradient information.
#define SMALL_EPSILON   0.01
 This lower limit below which a value is treated as zero. This avoids the discrete effect when using estimated edge gradient information.
#define ORTHOGAL_LOWER   58
 The lower bound of orthogality as encoded on the edge orientation image.
#define ORTHOGAL_UPPER   68
 The upper bound of orthogality as encoded on the edge orientation image.
#define ORI_BINS   32
 The number of histogram bins for analyzing orientation of a connected component.
#define CC_DIMENSION_RATIO_LOWER   0.15
 Lower bound of the height to width ratio of a connected component.
#define CC_DIMENSION_RATIO_UPPER   5.0
 Upper bound of the height to width ratio of a connected component.
#define SIG_DIMENSION_RATIO_LOWER   0.17
 Lower bound of the height to width ratio of a grouped signature.
#define SIG_DIMENSION_RATIO_UPPER   1.33
 Upper bound of the height to width ratio of a grouped signature.
#define MAX_CC_DENSITY   0.5
 The max spatial density of a connected component.
#define MAX_CC_PER_REGION   50
 The max number of connected components allowed for a signature.

Functions

int comp (const void *entry1, const void *entry2)
 Comparison function for sorting text lines.


Define Documentation

#define CC_DIMENSION_RATIO_LOWER   0.15

Lower bound of the height to width ratio of a connected component.

#define CC_DIMENSION_RATIO_UPPER   5.0

Upper bound of the height to width ratio of a connected component.

#define EDGE_MAG_THRE   50

The threshold value for the edge intensity image.

#define LAMBDA_UPPER   10.0

This upper limit in the lambda value avoids the discrete effect when using estimated edge gradient information.

#define MAX_CC_DENSITY   0.5

The max spatial density of a connected component.

#define MAX_CC_PER_REGION   50

The max number of connected components allowed for a signature.

#define MAX_DATARUN_LENGTH   50

The length of the largest connected strip in the same line (either horizontal or vertical).

#define MAX_SIG_HEIGHT   600

The max height of signature at the initial coarse image scale.

#define MAX_SIG_SPACING   37

The max space between parts of signatures during contour grouping.

#define MIN_ORIENTATION_DIFF   8

The step value for a change in the edge orientation image.

#define ORI_BINS   32

The number of histogram bins for analyzing orientation of a connected component.

#define ORTHOGAL_LOWER   58

The lower bound of orthogality as encoded on the edge orientation image.

#define ORTHOGAL_UPPER   68

The upper bound of orthogality as encoded on the edge orientation image.

#define RESIZE_FILTER_WIDTH   3.0

The support size of the image resize filter.

#define SIG_DIMENSION_RATIO_LOWER   0.17

Lower bound of the height to width ratio of a grouped signature.

#define SIG_DIMENSION_RATIO_UPPER   1.33

Upper bound of the height to width ratio of a grouped signature.

#define SMALL_EPSILON   0.01

This lower limit below which a value is treated as zero. This avoids the discrete effect when using estimated edge gradient information.


Function Documentation

int comp ( const void *  entry1,
const void *  entry2 
)

Comparison function for sorting text lines.


SignatureDetectDOCLIB Library is an add-on of DOCLIB. DOCLIB is being developed under contract by a collaboration between:
The Laboratory for Language and Media Processing
Unviersity of Maryland, College Park
and
Booz | Allen | Hamilton

All Rights Reserved, 2003-2007