Android Question [SOLVED] text to picture (watermark)

madru · Nov 21, 2020

hi guys,

how can stamp some text into a picture taken from camEx without changing the original picture DPI, resolution, zoom etc., actually leave the picture as it is

i tried the two following approaches without real success

B4X:

Sub Camera1_PictureTaken (Data() As Byte)


    ' save the original picture'
    ' picture 1.jpg'
    camEx.SavePictureToFile(Data, rp.GetSafeDirDefaultExternal(""), "1.jpg")
    
    
    '############################################################################################################################################

    'does not deal with aspect ratio correctly (canvas.Initialize), or i am using it not correct'
    'picture out.jpg
    ImageView1.Bitmap = BytesToBitmap(Data)
    canvas.Initialize(ImageView1) ' canvas has the wrong x,y resolution now how, to resize for picture size
    canvas.DrawText("some text", ImageView1.Width/2 , ImageView1.Height - 20dip ,Typeface.DEFAULT , 15, Colors.Blue, "CENTER") 
    'ImageView1.Invalidate

    b = ImageView1.Bitmap
    Dim out As OutputStream
    out = File.OpenOutput(rp.GetSafeDirDefaultExternal(""), "out.jpg", False)
    b.WriteToStream(out, 100, "JPEG")
    out.Close
    '############################################################################################################################################

    'RSImageEffects 'zooms' somehow into the picture
    'picture out1.jpg
    Dim BitmapTemp As Bitmap
    BitmapTemp.Initialize3(BytesToBitmap(Data))
    BitmapTemp = rs.Watermark(BitmapTemp,"some text",BitmapTemp.Width/2 , BitmapTemp.Height - 20dip,Colors.red,255,80,False)
    
    Dim out As OutputStream
    out = File.OpenOutput(rp.GetSafeDirDefaultExternal(""), "out1.jpg", False)
    BitmapTemp.WriteToStream(out, 100, "JPEG")
    out.Close
    '############################################################################################################################################

    camEx.StartPreview 'restart preview


End Sub

pictures are reduced to 50% JPG quality due to upload limit

roumei · Nov 22, 2020

You need to make sure that the aspect ratio of the ImageView and the Image are the same.

Or you could use a mutable bitmap to preserve the original resolution and aspect ratio:

B4X:

   ' Load bitmap
    Dim bmpInput As Bitmap = LoadBitmap(File.DirAssets, "Test.jpg")
    
    ' Create a mutable bitmap and draw the input bitmap
    Dim bmpMutable As Bitmap
    bmpMutable.InitializeMutable(bmpInput.Width, bmpInput.Height)
    Dim cvs As Canvas
    cvs.Initialize2(bmpMutable)
    Dim DestRect As Rect
    DestRect.Initialize(0, 0, bmpInput.Width, bmpInput.Height)
    cvs.DrawBitmap(bmpInput, Null, DestRect)

    ' Watermark
    cvs.DrawText("some text", bmpInput.Width/2 , bmpInput.Height - 20dip ,Typeface.DEFAULT , 15, Colors.Blue, "CENTER")
    
    ' Write output bitmap
    Dim Out As OutputStream
    Out = File.OpenOutput(rp.GetSafeDirDefaultExternal(""), "TestOut.jpg", False)
    cvs.Bitmap.WriteToStream(Out, 100, "JPEG")
    Out.Close

madru · Nov 22, 2020

forgot about Mutable Bitmap, it is properly mentioned 1000+ times in the Forum

THX

Android Question [SOLVED] text to picture (watermark)

madru

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roumei

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madru

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Android Question [SOLVED] text to picture (watermark)

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