net.doo.snap.lib.detector

Class ContourDetector

java.lang.Object

net.doo.snap.lib.detector.ContourDetector

public class ContourDetector
extends java.lang.Object

EdgeDetectionSuite JNI wrapper class.

Field Summary

Fields

Modifier and Type	Field and Description
static int	IMAGE_FILTER_BINARIZED
static int	IMAGE_FILTER_COLOR_DOCUMENT
static int	IMAGE_FILTER_COLOR_ENHANCED
static int	IMAGE_FILTER_GRAY
static int	IMAGE_FILTER_NONE
static int	IMAGE_FILTER_PURE_BINARIZED

Constructor Summary

Constructors

Constructor and Description
ContourDetector()

Method Summary

Modifier and Type	Method and Description
static android.graphics.Bitmap	createBitmapFromEncodedData(byte[] data) Creates a ARGB_8888 Bitmap from an in-memory JPEG.
static android.graphics.Bitmap	createBitmapFromEncodedFile(java.lang.String fileName) Creates a ARGB_8888 Bitmap from encoded JPEG on file system
static android.graphics.Bitmap	createBitmapFromNV21(byte[] nv21, int width, int height) Converts a NV21 encoded image into a ARGB_8888 Bitmap (using fixed point arithmetics).
DetectionResult	detect(android.graphics.Bitmap bitmap) Tries to detect a polygon from the given image.
DetectionResult	detect(byte[] data) Tries to detect a polygon from the given image.
DetectionResult	detect(byte[] nv21, int width, int height) Tries to detect a polygon from the given image.
DetectionResult	detect(java.lang.String fileName) Tries to detect a polygon from the given file.
void	dispose() Disposes the native resources held by this instance.
double	getDetectionScore()
java.util.List<Line2D>	getHorizontalLines()
java.util.List<android.graphics.Point>	getPolygon()
java.util.List<android.graphics.PointF>	getPolygonF()
java.util.List<Line2D>	getVerticalLines()
android.graphics.Bitmap	processImage(android.graphics.Bitmap bitmap, java.util.List<android.graphics.Point> polygon, int imageFilter) Post processes an image, applying cropping and filters.
android.graphics.Bitmap	processImage(byte[] nv21, int width, int height, java.util.List<android.graphics.Point> polygon, int imageFilter) Post processes an image, applying cropping and filters.
android.graphics.Bitmap	processImage(byte[] data, java.util.List<android.graphics.Point> polygon, int imageFilter) Post processes an image, applying cropping and filters.
android.graphics.Bitmap	processImageAndRelease(android.graphics.Bitmap bitmap, java.util.List<android.graphics.PointF> polygon, int imageFilter) Same as processImageF(java.lang.String, java.util.List<android.graphics.PointF>, int), but it recycles the input Bitmap before creating a new one in Java heap.
android.graphics.Bitmap	processImageAndScale(byte[] encodedImage, java.util.List<android.graphics.PointF> polygon, int imageFilter, int biggestSide) Post processes an image (using floating point coordinates), applying cropping and filters and then scales image to given size.
android.graphics.Bitmap	processImageF(android.graphics.Bitmap bitmap, java.util.List<android.graphics.PointF> polygon, int imageFilter) Post processes an image (using floating point coordinates), applying cropping and filters.
android.graphics.Bitmap	processImageF(byte[] nv21, int width, int height, java.util.List<android.graphics.PointF> polygon, int imageFilter) Post processes an image (using floating point coordinates), applying cropping and filters.
android.graphics.Bitmap	processImageF(byte[] data, java.util.List<android.graphics.PointF> polygon, int imageFilter) Post processes an image (using floating point coordinates), applying cropping and filters.
android.graphics.Bitmap	processImageF(java.lang.String fileName, java.util.List<android.graphics.PointF> polygon, int imageFilter) Post processes an image, applying cropping and filters.
void	resetPolygonHistory() Calling this method will reset the polygon smoothing history.
void	setAcceptedAngleScore(double acceptedAngleScore) The minimum score in percent (0 - 100) of the perspective distortion to accept a detected document.
void	setAcceptedSizeScore(double acceptedSizeScore) The minimum size in percent (0 - 100) of the screen size to accept a detected document.

Methods inherited from class java.lang.Object

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

Field Detail

IMAGE_FILTER_NONE

public static final int IMAGE_FILTER_NONE

See Also:

Constant Field Values

IMAGE_FILTER_COLOR_ENHANCED

public static final int IMAGE_FILTER_COLOR_ENHANCED

See Also:

Constant Field Values

IMAGE_FILTER_GRAY

public static final int IMAGE_FILTER_GRAY

See Also:

Constant Field Values

IMAGE_FILTER_BINARIZED

public static final int IMAGE_FILTER_BINARIZED

See Also:

Constant Field Values

IMAGE_FILTER_COLOR_DOCUMENT

public static final int IMAGE_FILTER_COLOR_DOCUMENT

See Also:

Constant Field Values

IMAGE_FILTER_PURE_BINARIZED

public static final int IMAGE_FILTER_PURE_BINARIZED

See Also:

Constant Field Values

Constructor Detail

ContourDetector

public ContourDetector()

Method Detail

detect

public final DetectionResult detect(byte[] nv21,
                                    int width,
                                    int height)

Tries to detect a polygon from the given image.

Parameters:

nv21 - NV21 encoded camera image

width - Width of the image pixels

height - Height of the image in pixels

Returns:

A DetectionResult that gives information about the recognition state.

detect

public final DetectionResult detect(byte[] data)

Tries to detect a polygon from the given image.

Parameters:

data - Encoded image (e.g. a JPEG)

Returns:

A DetectionResult that gives information about the recognition state.

detect

public final DetectionResult detect(java.lang.String fileName)
                             throws java.io.IOException

Tries to detect a polygon from the given file.

Parameters:

fileName - Encoded file path (e.g. a JPEG)

Returns:

A DetectionResult that gives information about the recognition state.

Throws:

java.io.IOException

detect

public final DetectionResult detect(android.graphics.Bitmap bitmap)

Tries to detect a polygon from the given image.

Parameters:

bitmap - The image

Returns:

A DetectionResult that gives information about the recognition state.

processImage

public final android.graphics.Bitmap processImage(byte[] nv21,
                                                  int width,
                                                  int height,
                                                  java.util.List<android.graphics.Point> polygon,
                                                  int imageFilter)

Post processes an image, applying cropping and filters.

Parameters:

nv21 - NV21 encoded camera image

width - Width of the image pixels

height - Height of the image in pixels

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImage

public final android.graphics.Bitmap processImage(byte[] data,
                                                  java.util.List<android.graphics.Point> polygon,
                                                  int imageFilter)

Post processes an image, applying cropping and filters.

Parameters:

data - Encoded image (e.g. a JPEG)

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImage

public final android.graphics.Bitmap processImage(android.graphics.Bitmap bitmap,
                                                  java.util.List<android.graphics.Point> polygon,
                                                  int imageFilter)

Post processes an image, applying cropping and filters.

Parameters:

bitmap - The image to process

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImageF

public android.graphics.Bitmap processImageF(java.lang.String fileName,
                                             java.util.List<android.graphics.PointF> polygon,
                                             int imageFilter)
                                      throws java.io.IOException

Post processes an image, applying cropping and filters.

Parameters:

fileName - path to JPEG file

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

Throws:

java.io.IOException

processImageF

public final android.graphics.Bitmap processImageF(byte[] nv21,
                                                   int width,
                                                   int height,
                                                   java.util.List<android.graphics.PointF> polygon,
                                                   int imageFilter)

Post processes an image (using floating point coordinates), applying cropping and filters.

Parameters:

nv21 - NV21 encoded camera image

width - Width of the image pixels

height - Height of the image in pixels

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImageF

public final android.graphics.Bitmap processImageF(byte[] data,
                                                   java.util.List<android.graphics.PointF> polygon,
                                                   int imageFilter)

Post processes an image (using floating point coordinates), applying cropping and filters.

Parameters:

data - Encoded image (e.g. a JPEG)

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImageF

public final android.graphics.Bitmap processImageF(android.graphics.Bitmap bitmap,
                                                   java.util.List<android.graphics.PointF> polygon,
                                                   int imageFilter)

Post processes an image (using floating point coordinates), applying cropping and filters.

Parameters:

bitmap - The image to process

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImageAndScale

public final android.graphics.Bitmap processImageAndScale(byte[] encodedImage,
                                                          java.util.List<android.graphics.PointF> polygon,
                                                          int imageFilter,
                                                          int biggestSide)

Post processes an image (using floating point coordinates), applying cropping and filters and then scales image to given size.

Parameters:

encodedImage - The image to process

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

processImageAndRelease

public final android.graphics.Bitmap processImageAndRelease(android.graphics.Bitmap bitmap,
                                                            java.util.List<android.graphics.PointF> polygon,
                                                            int imageFilter)

Same as processImageF(java.lang.String, java.util.List<android.graphics.PointF>, int), but it recycles the input Bitmap before creating a new one in Java heap. This helps to reduce total memory footprint on Java side and therefore avoiding OutOfMemory errors.

Parameters:

bitmap - The image to process. Will be recycled after this method completes.

polygon - The detected polygon

imageFilter - Image filter type, one of IMAGE_FILTER_* or 0.

Returns:

The processed Bitmap.

getPolygon

public final java.util.List<android.graphics.Point> getPolygon()

Returns:

the detected polygon (if any) as absolute pixel coordinates.

getPolygonF

public final java.util.List<android.graphics.PointF> getPolygonF()

Returns:

the detected polygon (if any) as floating point coordinates in [0.f, 1.f[.

getDetectionScore

public final double getDetectionScore()

Returns:

the detection score (if any) as double value in [0.0, 100.0].

getVerticalLines

public final java.util.List<Line2D> getVerticalLines()

Returns:

Detected vertical lines

getHorizontalLines

public final java.util.List<Line2D> getHorizontalLines()

Returns:

Detected horizontal lines

setAcceptedAngleScore

public final void setAcceptedAngleScore(double acceptedAngleScore)

The minimum score in percent (0 - 100) of the perspective distortion to accept a detected document. Default is 75.0. Set lower values to accept more perspective distortion. Warning: Lower values result in more blurred document images.

Parameters:

acceptedAngleScore -

setAcceptedSizeScore

public final void setAcceptedSizeScore(double acceptedSizeScore)

The minimum size in percent (0 - 100) of the screen size to accept a detected document. It is sufficient that height or width match the score. Default is 80.0. Warning: Lower values result in low resolution document images.

Parameters:

acceptedSizeScore -

resetPolygonHistory

public final void resetPolygonHistory()

Calling this method will reset the polygon smoothing history.

dispose

public void dispose()

Disposes the native resources held by this instance.

createBitmapFromEncodedData

public static final android.graphics.Bitmap createBitmapFromEncodedData(byte[] data)

Creates a ARGB_8888 Bitmap from an in-memory JPEG.

Parameters:

data - JPEG data.

Returns:

The decoded Bitmap.

createBitmapFromEncodedFile

public static final android.graphics.Bitmap createBitmapFromEncodedFile(java.lang.String fileName)
                                                                 throws java.io.IOException

Creates a ARGB_8888 Bitmap from encoded JPEG on file system

Parameters:

fileName - path to JPEG file

Returns:

The decoded Bitmap.

Throws:

java.io.IOException

createBitmapFromNV21

public static final android.graphics.Bitmap createBitmapFromNV21(byte[] nv21,
                                                                 int width,
                                                                 int height)

Converts a NV21 encoded image into a ARGB_8888 Bitmap (using fixed point arithmetics).

Parameters:

nv21 - Bytes to decode.

width - The width of the image.

height - The height of the image.

Returns:

The decoded image as a Bitmap.