Android Question JPEG byte array to Bitmap or BD

canalrun · Jun 3, 2014

Instead of setting the bitmap with Imageview.Bitmap=, try using Imageview.background=bd. Of course first you need to Dim bd as BitmapDrawable and then bd.Initialize with the JPG you took from camera. Then only set Imageview.background=bd
Inman, May 2, 2011

http://www.b4x.com/android/forum/threads/from-camera-to-imageview.8952/#post-49800

Hello,
I found the previous post from long ago. This is exactly what I want to do, but I'm lost on the bd.initialize step.

I'm using Erel's Camera and CameraEX examples. He has the Sub:

B4X:

Sub Camera1_Preview (PreviewPic() As Byte)
    If DateTime.Now > lastPreviewSaved + IntervalMs Then
        Dim jpeg() As Byte = camEx.PreviewImageToJpeg(PreviewPic, 70)
        lastPreviewSaved = DateTime.Now
        CallSubDelayed2(Communicator, "Send", jpeg)
    End If
End Sub

Basically he ends up with the byte array named jpeg. This is a compressed representation of the bitmap from the camera preview. I plan to send this data to another android device, then I would like to show the JPEG in an ImageView.Bitmap or Panel.Background. I would prefer to use the byte array – not working via files as an interim step.

So you have the byte array jpeg(). Somehow you want to initialize a bitmap or bitmap drawable from the byte array:

bd.initialize(??? what ???)

I have a feeling an input stream from bytes will be in there somewhere, but I just can't seem to make the full connection.

Any help?

Thanks,
Barry.

stevel05 · Jun 3, 2014

I haven't tried it but InputStream has an InitializeFromBytesArray method, and the BitMap Initialize2 method requires an input stream.

Probably what you're looking for.

canalrun · Jun 4, 2014

Thank you. That's it!

B4X:

Sub Cam1_Preview (Prev() As Byte)
  Dim l As Long = DateTime.Now
 
  If ((l - lastPrev) >= PrevIntMs) Then
    Dim jpeg() As Byte = camEx.PreviewImageToJpeg(Prev, 70)

    Log("Cam1_Preview ms: " & (l - lastPrev) & " Size : " & Prev.Length & " " & jpeg.Length)
   
    Dim ins As InputStream
    Dim bmp As Bitmap
    Dim imgtest As ImageView
   
    ins.InitializeFromBytesArray(jpeg, 0, jpeg.Length)
    bmp.Initialize2(ins)
   
    imgtest.Initialize("")
    imgtest.Gravity = Gravity.FILL
   
    Activity.AddView(imgtest, 10dip, 10dip, 100dip, 100dip)
   
    imgtest.Bitmap = bmp
   
    imgtest.BringToFront

    lastPrev = l + 10000000 ' run once every 10 million msec
  End If
End Sub

When my phone is in portrait mode the JPEG is rotated -90°. When my phone is in landscape mode the JPEG appears right side up. I have seen this issue discussed many times – I will have to research the solution. But, I am very happy to have this working.

Barry.

Android Question JPEG byte array to Bitmap or BD

canalrun

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stevel05

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canalrun

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Android Question JPEG byte array to Bitmap or BD

canalrun

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