OutOfFocusQRReader ImageConverter Android CameraX

OutOfFocusQRReader is a library for reading QR codes from out-of-focus images on Android.

License

License

GroupId

GroupId

com.github.soranakk.oofqrreader
ArtifactId

ArtifactId

image-converter-androidx-camera
Last Version

Last Version

1.0.0
Release Date

Release Date

Type

Type

aar
Description

Description

OutOfFocusQRReader ImageConverter Android CameraX
OutOfFocusQRReader is a library for reading QR codes from out-of-focus images on Android.
Project URL

Project URL

https://github.com/soranakk/OutOfFocusQRReader
Source Code Management

Source Code Management

https://github.com/soranakk/OutOfFocusQRReader

Download image-converter-androidx-camera

How to add to project

<!-- https://jarcasting.com/artifacts/com.github.soranakk.oofqrreader/image-converter-androidx-camera/ -->
<dependency>
    <groupId>com.github.soranakk.oofqrreader</groupId>
    <artifactId>image-converter-androidx-camera</artifactId>
    <version>1.0.0</version>
    <type>aar</type>
</dependency>
// https://jarcasting.com/artifacts/com.github.soranakk.oofqrreader/image-converter-androidx-camera/
implementation 'com.github.soranakk.oofqrreader:image-converter-androidx-camera:1.0.0'
// https://jarcasting.com/artifacts/com.github.soranakk.oofqrreader/image-converter-androidx-camera/
implementation ("com.github.soranakk.oofqrreader:image-converter-androidx-camera:1.0.0")
'com.github.soranakk.oofqrreader:image-converter-androidx-camera:aar:1.0.0'
<dependency org="com.github.soranakk.oofqrreader" name="image-converter-androidx-camera" rev="1.0.0">
  <artifact name="image-converter-androidx-camera" type="aar" />
</dependency>
@Grapes(
@Grab(group='com.github.soranakk.oofqrreader', module='image-converter-androidx-camera', version='1.0.0')
)
libraryDependencies += "com.github.soranakk.oofqrreader" % "image-converter-androidx-camera" % "1.0.0"
[com.github.soranakk.oofqrreader/image-converter-androidx-camera "1.0.0"]

Dependencies

compile (2)

Group / Artifact Type Version
com.github.soranakk.oofqrreader : oofqrreader jar 1.0.0
org.jetbrains.kotlin : kotlin-stdlib jar 1.4.21

runtime (1)

Group / Artifact Type Version
androidx.camera » camera-core jar 1.0.0-rc03

Project Modules

There are no modules declared in this project.

OutOfFocusQRReader

OutOfFocusQRReader is a library for reading QR Code from out-of-focus images on Android.

This library uses the OpenCV library.

“QR Code” is a registered trademark of DENSO WAVE INCORPORATED.

Install

Download OpenCV

Download the latest version of the OpenCV Android library from the official OpenCV web page.

https://opencv.org/releases/

Extract zip and move SDK folder

Extract the files the downloaded zip file and move the SDK folder to your project root folder.

Install OpenCV SDK

Edit the settings.gradle file in your project and sync your project:

// add
include ':sdk'

Install OutOfFocusQRReader

Edit the build.gradle file in your project:

repositories {
    mavenCentral()
}

dependencies {
    // OpenCV sdk
    implementation project(':sdk')

    // core
    implementation 'com.github.soranakk.oofqrreader:oofqrreader:1.0.0'
}

Usage

Create ImageData

Example using Camera2API

dependencies {
    ...

    implementation 'com.github.soranakk.oofqrreader:image-converter-android-camera:1.0.0'
}
val imageConverter = Camera2ApiImageConverter()
ImageReader.newInstance(width, height, ImageFormat.YUV_420_888, 1)
    .apply {
        setOnImageAvailableListener({ reader ->
            reader?.acquireLatestImage()?.let { image ->
                val imageData = imageConverter.convertImage(image)
                ... read QR Code
                image.close()
            }
        }, workerHandler)

Example using CameraXAPI

dependencies {
    ...

    implementation 'com.github.soranakk.oofqrreader:image-converter-androidx-camera:1.0.0'
}
val imageConverter = CameraXApiImageConverter()
val imageAnalysis = ImageAnalysis.Builder()
  .setTargetRotation(Surface.ROTATION_0)
  .setTargetResolution(Size(1280, 720))
  .setBackpressureStrategy(ImageAnalysis.STRATEGY_KEEP_ONLY_LATEST)
  .build()
  .also {
      it.setAnalyzer(cameraExecutor, ImageAnalysis.Analyzer { image ->
          val imageData = imageConverter.convertImage(image)
          ... read QR Code
          image.close()
      })
  }

Create QRCodeDecoder

Example using MLKit:

dependencies {
    ...

    implementation 'com.github.soranakk.oofqrreader:decoder-mlkit:1.0.0'
    implementation 'com.google.mlkit:barcode-scanning:16.1.1'
}
val mlKitDecoder = MLKitDecoder()

Example using ZXing:

dependencies {
    ...

    implementation 'com.github.soranakk.oofqrreader:decoder-zxing:1.0.0'
    implementation "com.google.zxing:core:3.4.1"
}
val zxingDecoder = ZxingDecoder()

If your app require Android minSdkVersion less than 24, see https://github.com/zxing/zxing/issues/1170 and demoApp's build.gradle

Example using OpenCV:

dependencies {
    ...

    implementation 'com.github.soranakk.oofqrreader:decoder-opencv:1.0.0'
}
val openCVDecoder = OpenCVDecoder()

Read QR code

val qrReader = MultiFilterQRCodeReader(someDecoder)
val result = qrReader.detectAndRead(image)

See demoApp for more info.

Appendix

How to improve accuracy

Estimate the area where a QR code exist

Estimate the area where a QR code exists by using the large contrast between the QR code and the background.

  1. Make the input image grayscale
  2. Binarize with Otsu's method
  3. Use Imgproc.erode to thicken the dots in a QR code and turn them into black squares.
  4. Use Imgproc.findContours to get the black square area

Adjust the image

Further improve the accuracy by processing the image of the estimated area using various Image Filters. The features of each ImageFilter implemented are as follows.

GaussianThresholdFilter

Binarize with a weighted average using Gaussian as a threshold at a fixed block size.

Input image

image_1.png

Estimate the area where a QR code exists

image_2.png

After applying the image filter

image_3.png

ThresholdOtsuFilter

Binarize Otsu's method.

Input image

image_1.png

Estimate the area where a QR code exists

image_2.png

After applying the image filter

image_3.png

OverexposureFilter

A filter for reading overexposed QR codes by setting a threshold so that even almost white areas become black. Most input images output a black image, but under certain circumstances this filter works well. For example, displaying a QR code on a smartphone will result in overexposure due to the strong backlight of the smartphone.

Input image

image_1.png

Estimate the area where a QR code exists

image_2.png

After applying the image filter

image_3.png

Versions

Version
1.0.0