B4J Question [Server] GetImage WriteToStream

enrfortin · May 17, 2024

Hi, I am using this project as the basis for a server application.

Tesseract-clipboard: OCR images stored in clipboard

Hi, I made a tesseract-ocr ui frontend, which will convert images stored in the clipboard into texts. Different from https://www.b4x.com/android/forum/threads/screen-ocr-in-5-minutes-and-50-lines.90655/, my version is very simple. It utilizes the system's screencapture shortcut to store images...

www.b4x.com

I tested the application and it works very well but it is a desktop application.
and I don't know how I can do this in b4j server.

In desktop app:

Dim out As OutputStream
        out=File.OpenOutput(File.Combine(File.DirApp,"tesseract-ocr"),"image.png",False)
        ImageView1.GetImage.WriteToStream(out)
        out.Close

and tried to do this without success:

bj4[server]:

        Dim out As OutputStream
        out=File.OpenOutput(File.Combine(File.DirApp,"tesseract-ocr"),"image.png",False)
      
    Dim nombreArchivoTemporal As String = Main.NombreArchivo
    Dim imageData() As Byte = File.ReadBytes(File.DirApp & "/up", nombreArchivoTemporal)
    Dim lengnt As String = nombreArchivoTemporal.Length
    out=File.OpenOutput(File.Combine(File.DirApp,"tesseract-ocr"),"image.png",False)
    out.WriteBytes(imageData, 0, lengnt)

    out.Close

the image is uploaded to the directory

File.DirApp & "/up"

and the name of the image I save here when uploading the image

Dim nombreArchivoTemporal As String = Main.NombreArchivo

I would appreciate any help or examples that can be provided.

jahswant · May 17, 2024

B4X:

Sub Handle(req As ServletRequest, resp As ServletResponse)
    Try
Dim img() As Byte = FileToBytes(File.DirAssets,"no_image_available.png")
Dim Inp As InputStream
Inp.InitializeFromBytesArray(img, 0, img.Length)
File.Copy2(Inp, resp.OutputStream)
StopMessageLoop
Catch
Log(LastException)
End Try
End Sub

Sub FileToBytes (Dir As String, FileName As String) As Byte()
    Return Bit.InputStreamToBytes(File.OpenInput(Dir, FileName))
End Sub

enrfortin · May 17, 2024

jahswant said:

B4X:

Sub Handle(req As ServletRequest, resp As ServletResponse)
    Try
Dim img() As Byte = FileToBytes(File.DirAssets,"no_image_available.png")
Dim Inp As InputStream
Inp.InitializeFromBytesArray(img, 0, img.Length)
File.Copy2(Inp, resp.OutputStream)
StopMessageLoop
Catch
Log(LastException)
End Try
End Sub

Sub FileToBytes (Dir As String, FileName As String) As Byte()
    Return Bit.InputStreamToBytes(File.OpenInput(Dir, FileName))
End Sub

Thanks I was able to adapt the code:

Process Image:

Sub ProcessImage
    Try
        ' Patch of the upload image.
        Dim uploadedImagePath As String = File.Combine(File.DirApp & "/up", "")

        ' Open OutputStream for output image
        Dim Inp As InputStream = File.OpenInput(uploadedImagePath,Main.NombreArchivo)
        
        ' Open OutputStream for output image
        Dim out As OutputStream = File.OpenOutput(File.DirApp & "/tesseract-ocr", "image.png", False)
        
        ' Copy image from InputStream to OutputStream
        File.Copy2(Inp, out)

        ' Close streams
        out.Close

        ' Here you can call Tesseract or do any additional processing with the image.
        scan
    Catch
        Log(LastException)
    End Try
End Sub

B4J Question [Server] GetImage WriteToStream

enrfortin

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jahswant

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enrfortin

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