B4A Library 1D and 2D Barcode Scanner with ZXING - another Barcode Scanner that is 100% embedded in B4A

Johan Schoeman

Expert
Licensed User
The attached project wraps the ZXING part of this Github project. I have not tested all the barcode formats but it should scan the following types:

BarcodeFormat.UPC_A
BarcodeFormat.UPC_E
BarcodeFormat.EAN_13
BarcodeFormat.EAN_8
BarcodeFormat.RSS_14
BarcodeFormat.CODE_39
BarcodeFormat.CODE_93
BarcodeFormat.CODE_128
BarcodeFormat.ITF
BarcodeFormat.CODABAR
BarcodeFormat.QR_CODE
BarcodeFormat.DATA_MATRIX
BarcodeFormat.PDF_417

Please take note of the xml files in the /Objects/res/layout and Objects/res/values folders of the B4A project should you start a new project from scratch.

Posting the following:
1. B4A project demonstrating the Barcode Scanner
2. B4A library files - copy them to your additional library folder
3. You also need android-support.v4.jar and core-3.2.1.jar to be in your additional library folder. I have zipped them together and you can download them from this link:
https://www.dropbox.com/s/h9ts6cjfoo5et6h/core-3.2.1.zip?dl=0

You can use it in portrait mode and landscape mode by changing the B4A project's attribute and the code in the Designer:
#SupportedOrientations: portrait

B4X:
zx1.Left = 2%x
zx1.Top = 5%y
zx1.Width = 96%x
zx1.Height = 80%y

b1.Left = 2%x
b1.Top = zx1.Bottom + 2%y
b1.Width = 15%x
b1.Height = 10%y

b2.Left = 45%x
b2.Top = zx1.Bottom + 2%y
b2.Width = 15%x
b2.Height = 10%y

b3.Left = 83%x
b3.Top = zx1.Bottom + 2%y
b3.Width = 15%x
b3.Height = 10%y
1.png



2.png

Sample code:
B4X:
#Region  Project Attributes
    #ApplicationLabel: ZxingBarcodeScanner
    #VersionCode: 1
    #VersionName:
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: portrait
    #CanInstallToExternalStorage: False
#End Region

#Region  Activity Attributes
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

    Private zx1 As ZxingBarcodeScanner
    Private b1 As Button
    Private b2 As Button
    Private b3 As Button
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("main")

    zx1.LaserColor = Colors.Yellow
    zx1.MaskColor = Colors.ARGB(150, 0, 0, 200)
    zx1.BorderColor = Colors.Magenta
    zx1.BorderStrokeWidth = 5
    zx1.BorderLineLength = 40
    zx1.Visible = False

End Sub

Sub Activity_Resume


End Sub

Sub Activity_Pause (UserClosed As Boolean)
    zx1.Visible = False
    zx1.stopScanner

End Sub


Sub b1_Click

    zx1.toggleFlash

End Sub

Sub b2_Click

    zx1.Visible = True
    zx1.startScanner

End Sub

Sub b3_Click

    zx1.Visible = False
    zx1.stopScanner

End Sub

Sub zx1_scan_result (scantext As String, scanformat As String)

    Log ("B4A scan text = " & scantext)
    Log ("B4A scan format = " & scanformat)


End Sub
The library:

ZxingBarcodeScanner
Author:
Github: Dushyanth Maguluru, Wrapped by: Johan Schoeman
Version: 1
ZxingBarcodeScanner
Events:

  • scan_result (scantext As String, scanformat As String)
Fields:
  • ba As BA
Methods:
  • BringToFront
  • DesignerCreateView (base As PanelWrapper, lw As LabelWrapper, props As Map)
  • Initialize (EventName As String)
  • Invalidate
  • Invalidate2 (arg0 As Rect)
  • Invalidate3 (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int)
  • IsInitialized As Boolean
  • RemoveView
  • RequestFocus As Boolean
  • SendToBack
  • SetBackgroundImage (arg0 As Bitmap)
  • SetColorAnimated (arg0 As Int, arg1 As Int, arg2 As Int)
  • SetLayout (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int)
  • SetLayoutAnimated (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int, arg4 As Int)
  • SetVisibleAnimated (arg0 As Int, arg1 As Boolean)
  • handleResult (rawResult As Result)
  • startScanner
  • stopScanner
  • toggleFlash
Permissions:
  • android.permission.CAMERA
  • android.permission.FLASHLIGHT
Properties:
  • Background As Drawable
  • BorderColor As Int [write only]
  • BorderLineLength As Int [write only]
  • BorderStrokeWidth As Int [write only]
  • Color As Int [write only]
  • Enabled As Boolean
  • Height As Int
  • LaserColor As Int [write only]
  • Left As Int
  • MaskColor As Int [write only]
  • Tag As Object
  • Top As Int
  • Visible As Boolean
  • Width As Int
You can download and test any posting of mine in this thread but if you want to use it then you need to
 

Attachments

Last edited:

Johan Schoeman

Expert
Licensed User
Very nice.

You should add in the title "barcode and QR code" as it seems to work also with QR codes !
Yes, see post #1 for the barcode formats that is should be able to scan
 

susu

Well-Known Member
Licensed User
Thank you Johan. Is this lib different your other barcode libs?
 

Johan Schoeman

Expert
Licensed User
Thank you Johan. Is this lib different your other barcode libs?
Yes, it is a different Github project that I have wrapped. It seems to be more responsive than some of the other barcode scanning projects that I have wrapped
 

jrat

Member
Licensed User
I'am trying lib and get the error
Installing file.
PackageAdded: package:JHS.ZxingBarcodeScanner
** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
android.content.res.Resources$NotFoundException: Resource ID #0x0
at android.content.res.Resources.getValue(Resources.java:1163)
at android.content.res.Resources.getColor(Resources.java:845)
at main.java.me.dm7.barcodescanner.core.ViewFinderView.<init>(ViewFinderView.java:39)
at main.java.me.dm7.barcodescanner.core.BarcodeScannerView.createViewFinderView(BarcodeScannerView.java:57)
at main.java.me.dm7.barcodescanner.core.BarcodeScannerView.setupLayout(BarcodeScannerView.java:40)
at main.java.me.dm7.barcodescanner.core.BarcodeScannerView.setupCameraPreview(BarcodeScannerView.java:70)
at main.java.me.dm7.barcodescanner.core.CameraHandlerThread$1$1.run(CameraHandlerThread.java:31)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5105)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:792)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:608)
at dalvik.system.NativeStart.main(Native Method)
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = false **
 

Johan Schoeman

Expert
Licensed User
Posting updated B4A library files only. It adds no new methods to the B4A project. Added a notification sound upon a successful scan in the library. You would still require the 2 x jar files mentioned in point 3 of post #1
 

Attachments

JackKirk

Well-Known Member
Licensed User
Johan,

Firstly thanks for building this library.

Some months ago I wrote a B4A app that scans barcodes, amongst other things.

At the time I used the original ABZXing library:

https://www.b4x.com/android/forum/threads/abzxing-barcode-reader.7303/

One of the main reasons for using this library, rather than one of the "built-in" options, was that the native ZXing app has a unique setting that allows you to set torch mode to auto - meaning that the torch automatically turns on in poor light conditions - an important consideration for my app which will be used in all sorts of light conditions by all sorts of people - some of whom will have great difficulty just holding a phone to allow the barcode to focus let alone toggling a torch on/off.

I subsequently ported the app to B4I - the iBarcode library was equally deficient but I eventually managed to solve this, see:

https://www.b4x.com/android/forum/t...roid-zxing-app-with-full-torch-control.63177/

This B4I app actually uses the camera on the torch side to sense ambient light conditions.

I am now revisiting the original B4A app and have discovered, to my dismay, that the native ZXing app actually uses the light sensor on the screen side of my Samsung S5, not a sensor on the torch side. This can be decidedly less than perfect in certain lighting conditions e.g. where the light source is behind the user forcing him to shadow the barcode by the phone.

I have been playing around with the CameraEx class, as modified by Jim Brown:

https://www.b4x.com/android/forum/t...ibrary-functionality.23801/page-8#post-191819

This has GetSupportedFlashModes and get/setFlashMode subs that burrow into the low level code via the Reflections library (way out of my league).

A bit of experimentation with this class on my Samsung S5 with the Auto flash mode suggests that it is actually turning the torch on when light conditions on the torch side are poor - which is what I am after.

So my question to you is: how hard would it be to add functionality to your library that adds an Auto torch capability, possibly similar to the GetSupportedFlashModes and get/setFlashMode subs in the CameraEx class?

Thanks in anticipation...
 
Last edited:

Johan Schoeman

Expert
Licensed User
Johan,

Firstly thanks for building this library.

Some months ago I wrote a B4A app that scans barcodes, amongst other things.

At the time I used the original ABZXing library:

https://www.b4x.com/android/forum/threads/abzxing-barcode-reader.7303/

One of the main reasons for using this library, rather than one of the "built-in" options, was that the native ZXing app has a unique setting that allows you to set torch mode to auto - meaning that the torch automatically turns on in poor light conditions - an important consideration for my app which will be used in all sorts of light conditions by all sorts of people - some of whom will have great difficulty just holding a phone to allow the barcode to focus let alone toggling a torch on/off.

I subsequently ported the app to B4I - the iBarcode library was equally deficient but I eventually managed to solve this, see:

https://www.b4x.com/android/forum/t...roid-zxing-app-with-full-torch-control.63177/

This B4I app actually uses the camera on the torch side to sense ambient light conditions.

I am now revisiting the original B4A app and have discovered, to my dismay, that the native ZXing app actually uses the light sensor on the screen side of my Samsung S5, not a sensor on the torch side. This can be decidedly less than perfect in certain lighting conditions e.g. where the light source is behind the user forcing him to shadow the barcode by the phone.

I have been playing around with the CameraEx class, as modified by Jim Brown:

https://www.b4x.com/android/forum/t...ibrary-functionality.23801/page-8#post-191819

This has GetSupportedFlashModes and get/setFlashMode subs that burrow into the low level code via the Reflections library (way out of my league).

A bit of experimentation with this class on my Samsung S5 with the Auto flash mode suggests that it is actually turning the torch on when light conditions on the torch side are poor - which is what I am after.

So my question to you is: how hard would it be to add functionality to your library that adds an Auto torch capability, possibly similar to the GetSupportedFlashModes and get/setFlashMode subs in the CameraEx class?

Thanks in anticipation...
I will try and add the AUTO option and if it works I will post an updated library. Give me time until this coming weekend to do the mods and to test them
 

JackKirk

Well-Known Member
Licensed User
Johan,

Just an additional thought - if you get it to work and there is some sort of threshold value which triggers the torch to automatically turn on - could you expose the threshold so it is adjustable?

Thanks again...
 

Johan Schoeman

Expert
Licensed User
Johan,

Just an additional thought - if you get it to work and there is some sort of threshold value which triggers the torch to automatically turn on - could you expose the threshold so it is adjustable?

Thanks again...
Have amended the code in the wrapper and in the original Github project to allow for the torch mode to be switched either manually or automatically. Please note that it uses the light sensor of your device when you set it in AUTO mode in order to determine if the torch should be switched on or off based on the lower and upper ambient light settings. I have also added code so that the upper and lower ambient light threshold values can be set from B4A for the AUTO mode. Also added an event to the B4A project that will be raised when the ambient light (as measured by the light sensor) changes.

Posting the following:
1. Updated B4A project demonstrating the added features
2. Updated B4A library files. Please note that you will still need the jar files from this link to also be in your additional library folder as what I have posted in post #1 of this thread: https://www.dropbox.com/s/h9ts6cjfoo5et6h/core-3.2.1.zip?dl=0

Sample code:

B4X:
#Region  Project Attributes
    #ApplicationLabel: ZxingBarcodeScanner
    #VersionCode: 1
    #VersionName:
    'SupportedOrientations possible values: unspecified, landscape or portrait.
    #SupportedOrientations: landscape
    #CanInstallToExternalStorage: False
#End Region

#Region  Activity Attributes
    #FullScreen: False
    #IncludeTitle: True
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.

End Sub

Sub Globals
    'These global variables will be redeclared each time the activity is created.
    'These variables can only be accessed from this module.

    Private zx1 As ZxingBarcodeScanner
    Private b1 As Button
    Private b2 As Button
    Private b3 As Button
End Sub

Sub Activity_Create(FirstTime As Boolean)
    'Do not forget to load the layout file created with the visual designer. For example:
    Activity.LoadLayout("main")
   
    zx1.LaserColor = Colors.Yellow
    zx1.MaskColor = Colors.ARGB(150, 0, 0, 200)
    zx1.BorderColor = Colors.Magenta
    zx1.BorderStrokeWidth = 5
    zx1.BorderLineLength = 40
   
    zx1.LowerLuxLimit = 500.0              'ADDED 5 MARCH 2016
    zx1.UpperLuxLimit = 1000.0             'ADDED 5 MARCH 2016
    zx1.AutoTorchMode = False              'ADDED 5 MARCH 2016
   
    zx1.Visible = False

End Sub

Sub Activity_Resume
   

End Sub

Sub Activity_Pause (UserClosed As Boolean)
    zx1.Visible = False
    zx1.stopScanner

End Sub


Sub b1_Click
   
    zx1.toggleFlash
   
End Sub

Sub b2_Click
   
    zx1.Visible = True
    zx1.startScanner
   
End Sub

Sub b3_Click
   
    zx1.Visible = False
    zx1.stopScanner
   
End Sub

Sub zx1_scan_result (scantext As String, scanformat As String)
   
    Log ("B4A scan text = " & scantext)
    Log ("B4A scan format = " & scanformat)
   
   
End Sub


Sub zx1_ambient_light_changed (ambientLight As Float)             'ADDED 5 MARCH 2016
   
    Log ("Ambient Light Lux Value = " & zx1.AmbientLightLux)      'ADDED 5 MARCH 2016
   
End Sub
Updated Library:

ZxingBarcodeScanner
Author:
Github: Dushyanth Maguluru, Wrapped by: Johan Schoeman
Version: 1
  • ZxingBarcodeScanner
    Events:
    • ambient_light_changed (ambientLight As Float)
    • scan_result (scantext As String, scanformat As String)
    Fields:
    • ba As BA
    Methods:
    • BringToFront
    • DesignerCreateView (base As PanelWrapper, lw As LabelWrapper, props As Map)
    • Initialize (EventName As String)
    • Invalidate
    • Invalidate2 (arg0 As Rect)
    • Invalidate3 (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int)
    • IsInitialized As Boolean
    • RemoveView
    • RequestFocus As Boolean
    • SendToBack
    • SetBackgroundImage (arg0 As Bitmap)
    • SetColorAnimated (arg0 As Int, arg1 As Int, arg2 As Int)
    • SetLayout (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int)
    • SetLayoutAnimated (arg0 As Int, arg1 As Int, arg2 As Int, arg3 As Int, arg4 As Int)
    • SetVisibleAnimated (arg0 As Int, arg1 As Boolean)
    • handleResult (rawResult As Result)
    • startScanner
    • stopScanner
    • toggleFlash
      Toggle the Torch between ON and OFF
    Permissions:
    • android.permission.CAMERA
    • android.permission.FLASHLIGHT
    Properties:
    • AmbientLightLux As Float [read only]
      Get the current Lux value
    • AutoTorchMode As Boolean [write only]
      Set control of the Torch to Auto or Manual
    • Background As Drawable
    • BorderColor As Int [write only]
    • BorderLineLength As Int [write only]
    • BorderStrokeWidth As Int [write only]
    • Color As Int [write only]
    • Enabled As Boolean
    • Height As Int
    • LaserColor As Int [write only]
    • Left As Int
    • LowerLuxLimit As Float [write only]
      Switch ON the torch if the Lux value is lower than this
    • MaskColor As Int [write only]
    • Tag As Object
    • Top As Int
    • UpperLuxLimit As Float [write only]
      Switch OFF the torch if the Lux value is lower than this
    • Visible As Boolean
    • Width As Int
 

Attachments

Johan Schoeman

Expert
Licensed User
Forgot to mention in the above post...if you just touch the scanner while the scanner is active it will also toggle the torch. It works in conjunction with the "Toggle Flash" button. You can therefore switch on the torch with the button or by touching the scanner when the scanner is active and then switch it off again by either using the button or by touching the scanner.
 

JackKirk

Well-Known Member
Licensed User
Johan,

Let me commend you on your responsiveness - very impressive.

But (bet you knew that was coming)...

Firstly (minor) - you didn't update the version number in the XML - wasn't sure if I had installed the new library correctly.

Secondly (bug?) - when I configure your new example with LowerLuxLimit of 100 and AutoTorchMode = True the torch only momentarily flashes on when I [Start Scan].

Thirdly - on my Samsung S5 it is using the light sensor on the screen side - which is what the native ZXing app does but is not what is needed (have a look at my initial post #11)

From what I can see of both my Samsung S5 and iPhone 4S:
  • neither of them have a simple light sensor on the torch side.
  • both their built in camera apps will flash when set to auto-flash and light conditions are poor on the torch side.
  • the built in camera apps seem to be sensing light on the torch side through the camera.
I managed to resolve this for the iPhone/B4I version of my barcode app by a bit of Objective C, see:

https://www.b4x.com/android/forum/threads/a-solution-for-getting-ambient-light-brightness.63106/ (post #2)

This appears to take a photo and then analyse it for brightness - sounds dirty but it would appear this is the way the auto-flash works on iPhones.

I haven't found a low level way to something similar on B4A, however I have been mucking around with Jim Brown's extension of the CameraEx class:

https://www.b4x.com/android/forum/t...ibrary-functionality.23801/page-8#post-191819

where I have tricked up the Camera1_PictureTaken sub to analyse the picture just taken for "brightness" (the mathematical definition of which seems to be very open):
B4X:
'***********************************************************
'***********************************************************
'***********************************************************
'JK's brightness fudge
   
    Dim jpg As InputStream
    jpg.InitializeFromBytesArray(Data,0,Data.Length)

    Dim bmp As Bitmap
    bmp.Initialize2(jpg)
    jpg.Close

    Dim pixels(bmp.Width * bmp.Height) As Int
    Dim jo = bmp As JavaObject
    jo.RunMethod("getPixels", Array As Object(pixels, 0, bmp.Width, 0, 0, bmp.Width, bmp.Height))

    Dim start_dt, samples As Long
    Dim xxx, yyy, spacing, single_pix, rrr, ggg, bbb As Int
    Dim brightness As Double
    Dim log_msg As String
   
    log_msg=""
   
    For spacing = 0 To 6
       
        start_dt = DateTime.Now   

        brightness = 0
       
        samples = 0

        For xxx = 0 To bmp.Width - 1 Step Power(2, spacing)

            For yyy = 0 To bmp.Height - 1 Step Power(2, spacing)
           
                single_pix = pixels(xxx + yyy * bmp.Width)
                rrr = Bit.UnsignedShiftRight(Bit.And(single_pix, 0xff0000), 16)
                ggg = Bit.UnsignedShiftRight(Bit.And(single_pix, 0xff00), 8)
                bbb = Bit.And(single_pix, 0xff)
                'According to this webpage:
                'http://alienryderflex.com/hsp.html
                'following formula is close to as used by PhotoShop
                brightness = brightness + Sqrt(.299 * rrr * rrr + .587 * ggg * ggg + .114 * bbb * bbb)
                samples = samples + 1
       
            Next
       
        Next

        brightness = brightness / samples / 255

        log_msg = log_msg & CRLF & "brightness=" & NumberFormat2(brightness, 1, 4, 4, False) & " in " & (DateTime.Now - start_dt)  & " millisecs with 1 in " & Power(2, spacing) & " sampling"
   
    Next

    Msgbox(log_msg, "")

'***********************************************************
'***********************************************************
'***********************************************************
This also sounds dirty but seems to work well - it can analyse a 1920 x 1080 image with full 1:1 sampling in less than half a second.

I have attached the entire exercise as a zip below...
 

Attachments

Johan Schoeman

Expert
Licensed User
Johan,

Let me commend you on your responsiveness - very impressive.

But (bet you knew that was coming)...

Firstly (minor) - you didn't update the version number in the XML - wasn't sure if I had installed the new library correctly.

Secondly (bug?) - when I configure your new example with LowerLuxLimit of 100 and AutoTorchMode = True the torch only momentarily flashes on when I [Start Scan].

Thirdly - on my Samsung S5 it is using the light sensor on the screen side - which is what the native ZXing app does but is not what is needed (have a look at my initial post #11)

From what I can see of both my Samsung S5 and iPhone 4S:
  • neither of them have a simple light sensor on the torch side.
  • both their built in camera apps will flash when set to auto-flash and light conditions are poor on the torch side.
  • the built in camera apps seem to be sensing light on the torch side through the camera.
I managed to resolve this for the iPhone/B4I version of my barcode app by a bit of Objective C, see:

https://www.b4x.com/android/forum/threads/a-solution-for-getting-ambient-light-brightness.63106/ (post #2)

This appears to take a photo and then analyse it for brightness - sounds dirty but it would appear this is the way the auto-flash works on iPhones.

I haven't found a low level way to something similar on B4A, however I have been mucking around with Jim Brown's extension of the CameraEx class:

https://www.b4x.com/android/forum/t...ibrary-functionality.23801/page-8#post-191819

where I have tricked up the Camera1_PictureTaken sub to analyse the picture just taken for "brightness" (the mathematical definition of which seems to be very open):
B4X:
'***********************************************************
'***********************************************************
'***********************************************************
'JK's brightness fudge
  
    Dim jpg As InputStream
    jpg.InitializeFromBytesArray(Data,0,Data.Length)

    Dim bmp As Bitmap
    bmp.Initialize2(jpg)
    jpg.Close

    Dim pixels(bmp.Width * bmp.Height) As Int
    Dim jo = bmp As JavaObject
    jo.RunMethod("getPixels", Array As Object(pixels, 0, bmp.Width, 0, 0, bmp.Width, bmp.Height))

    Dim start_dt, samples As Long
    Dim xxx, yyy, spacing, single_pix, rrr, ggg, bbb As Int
    Dim brightness As Double
    Dim log_msg As String
  
    log_msg=""
  
    For spacing = 0 To 6
      
        start_dt = DateTime.Now  

        brightness = 0
      
        samples = 0

        For xxx = 0 To bmp.Width - 1 Step Power(2, spacing)

            For yyy = 0 To bmp.Height - 1 Step Power(2, spacing)
          
                single_pix = pixels(xxx + yyy * bmp.Width)
                rrr = Bit.UnsignedShiftRight(Bit.And(single_pix, 0xff0000), 16)
                ggg = Bit.UnsignedShiftRight(Bit.And(single_pix, 0xff00), 8)
                bbb = Bit.And(single_pix, 0xff)
                'According to this webpage:
                'http://alienryderflex.com/hsp.html
                'following formula is close to as used by PhotoShop
                brightness = brightness + Sqrt(.299 * rrr * rrr + .587 * ggg * ggg + .114 * bbb * bbb)
                samples = samples + 1
      
            Next
      
        Next

        brightness = brightness / samples / 255

        log_msg = log_msg & CRLF & "brightness=" & NumberFormat2(brightness, 1, 4, 4, False) & " in " & (DateTime.Now - start_dt)  & " millisecs with 1 in " & Power(2, spacing) & " sampling"
  
    Next

    Msgbox(log_msg, "")

'***********************************************************
'***********************************************************
'***********************************************************
This also sounds dirty but seems to work well - it can analyse a 1920 x 1080 image with full 1:1 sampling in less than half a second.

I have attached the entire exercise as a zip below...
Attached is the Java code. Change it to whatever might suite your needs. The changes that you require is not in the wrapper but in the code of the original project. What you are asking for is beyond the scope of the wrapper as it requires major changes to the original project code - some of which I have tried to accommodate in the last library that I have posted. I have already changed the original code more than what one should do - it just becomes so much more difficult to maintain the library when there are updates to the original project. So, if the library as it stands at present does not work for you then I suggest you either change the attached code (and recompile it into a lib) or choose something that works for you...;)

In order to compile the attached source code you will need to add a libs folder on the same folder level as the attached scr folder and have android-support-v4.jar and core-3.2.1.jar in the libs folder. You can download the two jars from here https://www.dropbox.com/s/h9ts6cjfoo5et6h/core-3.2.1.zip?dl=0. You also need to have them in your additional library folder.
 

Attachments

Johan Schoeman

Expert
Licensed User
Secondly (bug?) - when I configure your new example with LowerLuxLimit of 100 and AutoTorchMode = True the torch only momentarily flashes on when I [Start Scan].
I have set...
zx1.LowerLuxLimit = 30.0
...and it works just fine on my S4 mini. Unfortunately I am limited to the devices that I can test it on.
 

JackKirk

Well-Known Member
Licensed User
Johan,
I have set...
zx1.LowerLuxLimit = 30.0
...and it works just fine on my S4 mini. Unfortunately I am limited to the devices that I can test it on.
I re-installed your new example code, changed the top and bottom lines of these 3:
B4X:
    zx1.LowerLuxLimit = 100.0              'ADDED 5 MARCH 2016
zx1.UpperLuxLimit = 1000.0             'ADDED 5 MARCH 2016
zx1.AutoTorchMode = True              'ADDED 5 MARCH 2016
and recompiled it to my Samsung S5.

I then went into a totally dark room and launched it - same result as before - a momentary flash.

I then launched the native ZXing app (with setting [Use front light] > [Automatic]) under the same light conditions and the torch automatically came on and stayed on.

Attached is the Java code. Change it to whatever might suite your needs. The changes that you require is not in the wrapper but in the code of the original project. What you are asking for is beyond the scope of the wrapper as it requires major changes to the original project code - some of which I have tried to accommodate in the last library that I have posted. I have already changed the original code more than what one should do - it just becomes so much more difficult to maintain the library when there are updates to the original project. So, if the library as it stands at present does not work for you then I suggest you either change the attached code (and recompile it into a lib) or choose something that works for you...;)
I understand your position. I believe I can come up with a solution that works for me by using your library and code similar to what I alluded to in post #16.

I am also happy to post it as a class similar to what I have done for iOS:

https://www.b4x.com/android/forum/t...roid-zxing-app-with-full-torch-control.63177/

I was a bit reluctant to go down that path for a couple of reasons:

(1) you obviously are infinitely more versed in Java and wrapping of GitHub projects than I - you quite likely would be able to find a much more elegant solution than the rather dirty solution I am contemplating.

(2) from what I can see, you have pretty much taken ownership of "in-built" B4A barcode scanner solutions - I am new around here, not well versed in the local etiquette and not wanting to put anyone offside.

I would appreciate your response/s...
 

Johan Schoeman

Expert
Licensed User
B4X:
'***********************************************************
'***********************************************************
'***********************************************************
'JK's brightness fudge
 
    Dim jpg As InputStream
    jpg.InitializeFromBytesArray(Data,0,Data.Length)

    Dim bmp As Bitmap
    bmp.Initialize2(jpg)
    jpg.Close

    Dim pixels(bmp.Width * bmp.Height) As Int
    Dim jo = bmp As JavaObject
    jo.RunMethod("getPixels", Array As Object(pixels, 0, bmp.Width, 0, 0, bmp.Width, bmp.Height))

    Dim start_dt, samples As Long
    Dim xxx, yyy, spacing, single_pix, rrr, ggg, bbb As Int
    Dim brightness As Double
    Dim log_msg As String
 
    log_msg=""
 
    For spacing = 0 To 6
     
        start_dt = DateTime.Now 

        brightness = 0
     
        samples = 0

        For xxx = 0 To bmp.Width - 1 Step Power(2, spacing)

            For yyy = 0 To bmp.Height - 1 Step Power(2, spacing)
         
                single_pix = pixels(xxx + yyy * bmp.Width)
                rrr = Bit.UnsignedShiftRight(Bit.And(single_pix, 0xff0000), 16)
                ggg = Bit.UnsignedShiftRight(Bit.And(single_pix, 0xff00), 8)
                bbb = Bit.And(single_pix, 0xff)
                'According to this webpage:
                'http://alienryderflex.com/hsp.html
                'following formula is close to as used by PhotoShop
                brightness = brightness + Sqrt(.299 * rrr * rrr + .587 * ggg * ggg + .114 * bbb * bbb)
                samples = samples + 1
     
            Next
     
        Next

        brightness = brightness / samples / 255

        log_msg = log_msg & CRLF & "brightness=" & NumberFormat2(brightness, 1, 4, 4, False) & " in " & (DateTime.Now - start_dt)  & " millisecs with 1 in " & Power(2, spacing) & " sampling"
 
    Next

    Msgbox(log_msg, "")

'***********************************************************
'***********************************************************
'***********************************************************
What is the range of brightness values that you get from your code above? I am trying to get your requirement added. I get a brightness of 0.16 when I block the camera with my finger and the highest that I have seen it is about 0.48 (indoors when pointing the camera to the ceiling)
 
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