org.opencv.objdetect

Class BarcodeDetector

java.lang.Object

org.opencv.objdetect.GraphicalCodeDetector

org.opencv.objdetect.BarcodeDetector

public class BarcodeDetector
extends GraphicalCodeDetector

Field Summary

Fields inherited from class org.opencv.objdetect.GraphicalCodeDetector

nativeObj

Constructor Summary

Constructors

Modifier	Constructor and Description
	BarcodeDetector() Initialize the BarcodeDetector.
protected	BarcodeDetector(long addr)
	BarcodeDetector(String prototxt_path, String model_path) Initialize the BarcodeDetector.

Method Summary

Modifier and Type	Method and Description
static BarcodeDetector	__fromPtr__(long addr)
boolean	decodeWithType(Mat img, Mat points, List<String> decoded_info, List<String> decoded_type) Decodes barcode in image once it's found by the detect() method.
boolean	detectAndDecodeWithType(Mat img, List<String> decoded_info, List<String> decoded_type) Both detects and decodes barcode
boolean	detectAndDecodeWithType(Mat img, List<String> decoded_info, List<String> decoded_type, Mat points) Both detects and decodes barcode
protected void	finalize()
void	getDetectorScales(MatOfFloat sizes) Returns detector box filter sizes.
double	getDownsamplingThreshold() Get detector downsampling threshold.
double	getGradientThreshold() Get detector gradient magnitude threshold.
BarcodeDetector	setDetectorScales(MatOfFloat sizes) Set detector box filter sizes.
BarcodeDetector	setDownsamplingThreshold(double thresh) Set detector downsampling threshold.
BarcodeDetector	setGradientThreshold(double thresh) Set detector gradient magnitude threshold.

Methods inherited from class org.opencv.objdetect.GraphicalCodeDetector

decode, decode, decodeMulti, decodeMulti, detect, detectAndDecode, detectAndDecode, detectAndDecode, detectAndDecodeMulti, detectAndDecodeMulti, detectAndDecodeMulti, detectMulti, getNativeObjAddr

Methods inherited from class java.lang.Object

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

Constructor Detail

BarcodeDetector

protected BarcodeDetector(long addr)

BarcodeDetector

public BarcodeDetector()

Initialize the BarcodeDetector.

BarcodeDetector

public BarcodeDetector(String prototxt_path,
                       String model_path)

Initialize the BarcodeDetector. Parameters allow to load _optional_ Super Resolution DNN model for better quality.

Parameters:

prototxt_path - prototxt file path for the super resolution model

model_path - model file path for the super resolution model

Method Detail

__fromPtr__

public static BarcodeDetector __fromPtr__(long addr)

decodeWithType

public boolean decodeWithType(Mat img,
                              Mat points,
                              List<String> decoded_info,
                              List<String> decoded_type)

Decodes barcode in image once it's found by the detect() method.

Parameters:

img - grayscale or color (BGR) image containing bar code.

points - vector of rotated rectangle vertices found by detect() method (or some other algorithm). For N detected barcodes, the dimensions of this array should be [N][4]. Order of four points in vector<Point2f> is bottomLeft, topLeft, topRight, bottomRight.

decoded_info - UTF8-encoded output vector of string or empty vector of string if the codes cannot be decoded.

decoded_type - vector strings, specifies the type of these barcodes

Returns:

true if at least one valid barcode have been found

detectAndDecodeWithType

public boolean detectAndDecodeWithType(Mat img,
                                       List<String> decoded_info,
                                       List<String> decoded_type,
                                       Mat points)

Both detects and decodes barcode

Parameters:

img - grayscale or color (BGR) image containing barcode.

decoded_info - UTF8-encoded output vector of string(s) or empty vector of string if the codes cannot be decoded.

decoded_type - vector of strings, specifies the type of these barcodes

points - optional output vector of vertices of the found barcode rectangle. Will be empty if not found.

Returns:

true if at least one valid barcode have been found

detectAndDecodeWithType

public boolean detectAndDecodeWithType(Mat img,
                                       List<String> decoded_info,
                                       List<String> decoded_type)

Both detects and decodes barcode

Parameters:

img - grayscale or color (BGR) image containing barcode.

decoded_info - UTF8-encoded output vector of string(s) or empty vector of string if the codes cannot be decoded.

decoded_type - vector of strings, specifies the type of these barcodes

Returns:

true if at least one valid barcode have been found

getDownsamplingThreshold

public double getDownsamplingThreshold()

Get detector downsampling threshold.

Returns:

detector downsampling threshold

setDownsamplingThreshold

public BarcodeDetector setDownsamplingThreshold(double thresh)

Set detector downsampling threshold. By default, the detect method resizes the input image to this limit if the smallest image size is is greater than the threshold. Increasing this value can improve detection accuracy and the number of results at the expense of performance. Correlates with detector scales. Setting this to a large value will disable downsampling.

Parameters:

thresh - downsampling limit to apply (default 512) SEE: setDetectorScales

Returns:

automatically generated

getDetectorScales

public void getDetectorScales(MatOfFloat sizes)

Returns detector box filter sizes.

Parameters:

sizes - output parameter for returning the sizes.

setDetectorScales

public BarcodeDetector setDetectorScales(MatOfFloat sizes)

Set detector box filter sizes. Adjusts the value and the number of box filters used in the detect step. The filter sizes directly correlate with the expected line widths for a barcode. Corresponds to expected barcode distance. If the downsampling limit is increased, filter sizes need to be adjusted in an inversely proportional way.

Parameters:

sizes - box filter sizes, relative to minimum dimension of the image (default [0.01, 0.03, 0.06, 0.08])

Returns:

automatically generated

getGradientThreshold

public double getGradientThreshold()

Get detector gradient magnitude threshold.

Returns:

detector gradient magnitude threshold.

setGradientThreshold

public BarcodeDetector setGradientThreshold(double thresh)

Set detector gradient magnitude threshold. Sets the coherence threshold for detected bounding boxes. Increasing this value will generate a closer fitted bounding box width and can reduce false-positives. Values between 16 and 1024 generally work, while too high of a value will remove valid detections.

Parameters:

thresh - gradient magnitude threshold (default 64).

Returns:

automatically generated

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class GraphicalCodeDetector

Throws:

Throwable