Hi there...
If you already seen the example of Erel with Barcode/QRCode Reading-Scanner using ML / GMS Vision Lib... you will understand the simplicity... well i wanted to do the same with ocr having specific Region (orthogon-square) for cropping - recognizing the text from specific area....
* The B4XOCRPage based on OCR TextRecognition using ML Kit
** Will need also Camera2 Library and CamEX2...
The result saving in a public text string having it in "main.ocrresult"
The w and h is the size of Panel -> using for crop image and also showing the specific region of orthogon - capturing...
here we go:
If you already seen the example of Erel with Barcode/QRCode Reading-Scanner using ML / GMS Vision Lib... you will understand the simplicity... well i wanted to do the same with ocr having specific Region (orthogon-square) for cropping - recognizing the text from specific area....
* The B4XOCRPage based on OCR TextRecognition using ML Kit
** Will need also Camera2 Library and CamEX2...
The result saving in a public text string having it in "main.ocrresult"
The w and h is the size of Panel -> using for crop image and also showing the specific region of orthogon - capturing...
here we go:
B4X:
Sub Class_Globals
Private Root As B4XView 'ignore
Private xui As XUI 'ignore
Private pnlPreview As B4XView
Private camex As CamEx2
Private MyTaskIndex As Int
Private camtimer As Timer
Private IntervalBetweenPreviewsMs As Int = 500
Private recognizer As TextRecognizer
Private textResultLabel As Label
Private okreturn As Label
Dim w As Int = 200dip 'pnlPreview.Width / 2
Dim h As Int = 200dip 'pnlPreview.Height / 3
Private alreadyworks As Int = 0
End Sub
'You can add more parameters here.
Public Sub Initialize As Object
Return Me
End Sub
'This event will be called once, before the page becomes visible.
Private Sub B4XPage_Created (Root1 As B4XView)
Root = Root1
'load the layout to Root
Root.LoadLayout("camera_layout") ' Layout with only a Panel named pnlPreview
B4XPages.SetTitle(Me, "OCR Recognizing")
' Create label for OCR text
textResultLabel.Initialize("")
okreturn.Initialize("okreturn")
okreturn.TextColor=Colors.White
okreturn.TextSize=42
okreturn.Typeface = Typeface.MATERIALICONS
okreturn.Text=Chr(0xE86C)
okreturn.Gravity=Gravity.CENTER
textResultLabel.TextColor = Colors.White
textResultLabel.TextSize = 22
textResultLabel.Gravity = Gravity.CENTER
okreturn.Width=100dip
okreturn.Height=100dip
Root.AddView(okreturn,50%x-(okreturn.Width/2),100%y-(okreturn.Height*1),100dip,100dip)
Root.AddView(textResultLabel, 0, 20dip, 100%x, 50dip)
alreadyworks=0
recognizer.Initialize("Latin")
StartCamera
End Sub
Private Sub StartCamera
pnlPreview.Visible = True
camex.Initialize(pnlPreview)
Wait For (camex.OpenCamera(False)) Complete (TaskIndex As Int)
If TaskIndex > 0 Then
MyTaskIndex = TaskIndex
For Each size As CameraSize In camex.GetSupportedPreviewSizes
If size.Height <= 480 Then
camex.PreviewSize = size
Exit
End If
Next
Wait For (camex.PrepareSurface(MyTaskIndex)) Complete (Success As Boolean)
If Success Then
camex.StartPreview(MyTaskIndex, False)
AddCropOverlay
camtimer.Initialize("camtimer", IntervalBetweenPreviewsMs)
alreadyworks=1
camtimer.Enabled = True
Else
Log("Failed to prepare camera surface.")
End If
End If
End Sub
Private Sub AddCropOverlay
For i = pnlPreview.NumberOfViews - 1 To 0 Step -1
Dim v As View
v = pnlPreview.GetView(i)
If v.Tag.As(String).Contains("CropOverlay") Then
v.RemoveView
End If
Next
Dim overlay1 As B4XView = xui.CreatePanel("")
overlay1.SetColorAndBorder(xui.Color_ARGB(180, 0, 0, 0), 0dip, 0, 0dip)
overlay1.Tag = "CropOverlay1"
Dim left As Int = (pnlPreview.Width - w) / 2
Dim top As Int = (pnlPreview.Height - h) / 2
pnlPreview.AddView(overlay1, 0, 0, 100%x, top)
Dim overlay2 As B4XView = xui.CreatePanel("")
overlay2.SetColorAndBorder(xui.Color_ARGB(180, 0, 0, 0), 0dip, 0, 0dip)
overlay2.Tag = "CropOverlay2"
Dim left As Int = (pnlPreview.Width - w) / 2
Dim top As Int = (pnlPreview.Height - h) / 2
pnlPreview.AddView(overlay2, 0, top, left, h)
Dim overlay3 As B4XView = xui.CreatePanel("")
overlay3.SetColorAndBorder(xui.Color_ARGB(180, 0, 0, 0), 0dip, 0, 0dip)
overlay3.Tag = "CropOverlay3"
Dim left As Int = (pnlPreview.Width - w) / 2
Dim top As Int = (pnlPreview.Height - h) / 2
pnlPreview.AddView(overlay3, left+w, top, 100%x-(left+w), h)
Dim overlay4 As B4XView = xui.CreatePanel("")
overlay4.SetColorAndBorder(xui.Color_ARGB(180, 0, 0, 0), 0dip, 0, 0dip)
overlay4.Tag = "CropOverlay4"
Dim left As Int = (pnlPreview.Width - w) / 2
Dim top As Int = (pnlPreview.Height - h) / 2
pnlPreview.AddView(overlay4, 0, (top+h), 100%x, 100%y-(top+h))
Dim overlay As B4XView = xui.CreatePanel("")
overlay.SetColorAndBorder(xui.Color_Transparent, 3dip, xui.Color_Red, 0dip)
overlay.Tag = "CropOverlay"
Dim left As Int = (pnlPreview.Width - w) / 2
Dim top As Int = (pnlPreview.Height - h) / 2
pnlPreview.AddView(overlay, left, top, w, h)
If alreadyworks=1 Then camtimer.Enabled=True
End Sub
Private Sub camtimer_Tick
alreadyworks=0
camtimer.Enabled=False
Try
Dim bmp As Bitmap = camex.GetPreviewBitmap(800, 1280)
If bmp.IsInitialized = False Then Return
Dim b4xBmp As B4XBitmap = bmp
Dim cropped As B4XBitmap = CropFromOverlay(b4xBmp)
If cropped.IsInitialized = False Then Return
Wait For (recognizer.Recognize(cropped)) Complete (Result As TextRecognizerResult)
If Result.Success Then
If Result.text.trim<>"" Then
textResultLabel.Text = Result.Text.Replace(CRLF," ")
okreturn.Text=Chr(0xE86C)
End If
Else
'textResultLabel.Text = ""
'okreturn.Text=""
End If
Catch
Log(LastException)
End Try
camtimer.Enabled=True
alreadyworks=1
End Sub
Private Sub CropFromOverlay(sourceBmp As B4XBitmap) As B4XBitmap
For i = 0 To pnlPreview.NumberOfViews - 1
Dim v As B4XView = pnlPreview.GetView(i)
If v.Tag <> Null And v.Tag = "CropOverlay" Then
Dim scaleX As Float = sourceBmp.Width / pnlPreview.Width
Dim scaleY As Float = sourceBmp.Height / pnlPreview.Height
Dim x As Int = v.Left * scaleX
Dim y As Int = v.Top * scaleY
Dim w As Int = v.Width * scaleX
Dim h As Int = v.Height * scaleY
If x + w > sourceBmp.Width Or y + h > sourceBmp.Height Then Return Null
Return sourceBmp.Crop(x, y, w, h)
End If
Next
Return Null
End Sub
Private Sub B4XPage_Disappear
If camtimer.IsInitialized Then camtimer.Enabled = False
If camex.IsInitialized Then camex.Stop
End Sub
Private Sub B4XPage_Appear
If camex.IsInitialized Then StartCamera
End Sub
Private Sub okreturn_Click
Main.ocrresult=textResultLabel.Text
B4XPages.ClosePage(Me)
End Sub
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