Android Question CameraEX Work with images

[Addo]

i am doing the following to convert images to a string From the camera

Sub camera_Preview(Data() As Byte)
    
Dim sendtime As Long


sendtime = DateTime.Now


If sendtime - lastsendtimecam >= 500 Then


Dim jpeg() As Byte = camera1.PreviewImageToJpeg(Data, 20)

Dim rot As Int = camera1.CurrOrient
Dim ins As InputStream
Dim bmp As Bitmap
Dim bmpresize As Bitmap


ins.InitializeFromBytesArray(jpeg, 0, jpeg.Length)
bmp.Initialize2(ins)
ins.Close
bmp = RotateImage(bmp, rot)
bmpresize = CreateScaledBitmap(bmp,320, 240)

Dim imagetostring As String
Dim imgbyets() As Byte
imgbyets =  imagetobyets(bmpresize)

imagetostring = strutls.EncodeBase64(imgbyets)

'do send if needed

lastsendtimecam = DateTime.Now


End If



End Sub

every thing seems to work but the phone is lagging too much while this procedures begins , any idea on how to enhance the performance of current code to avoid lagging freezing ?

 

[JordiCP]

First of all, which preview size are you using? If you are sending 320x240, and this resolution is already supported by your camera (getSupportedPreviewSizes), make sure to select it as preview size, and all previous operations will be cheaper (and some unnecessary)
Also, usually the camera gives the preview frame in landscape mode. Your final image seems also in landscape, so the rotate function seems to do nothing in this case. Worth evaluating if it takes any time, as there can be surprises.

If the above is not enough, there are additional ways to optimize it all, depending on what is causing the bottleneck. You should measure time taken by each step, also the real preview size and jpeg size: this will help to sort if the problem is due to transmission bandwidth or processing delay.--> for instance, you could directly send the JPEG encoded in base64 (if you can re-build the bitmap on the other side based on this information).

 

[Erel]

1. Remove RotateImage and CreateScaledBitmap. There are better built-in methods.

2. Why do you need to encode it to base 64?

3. Better to do it like this:

bmp = bmp.Resize(320, 240, False) 'resize the image and only then rotate it
bmp = bmp.Rotate(rot)

 

[Addo]

Thanks for reply guys

2. Why do you need to encode it to base 64?

I am planing to save this data in a database I thought it will be necessary if the image string encoded

 

[Erel]

I am planing to save this data in a database I thought it will be necessary if the image string encoded

Not needed at all. Store the raw bytes in a BLOB field.