B4A Library [B4X] Library Base64 encode/decode Image and File library

From an idea of the Great Peter ( https://www.b4x.com/android/forum/threads/base64-encode-decode-image-library.31031/ ) "...in attached the library for decoding base64 image stings, so I quickly put together this simple but effective base64 encode/decode images library for others to use..."

In version 1.13 also added the BaseAnyFileToString + Base64StringToAnyFile method. To convert any file to Base64.

The library is for B4X (Tested with B4J, B4A, B4i)

The Example Code:

B4X:
'File 653 kb
    File.Copy(File.DirAssets, "653.jpg", File.DirInternal,"653.jpg")
    Sleep(300)

    'Image to Encode64
    Dim base As String = Base64EncodeDecodeImage.Base64ImageToString(File.DirInternal,"653.jpg")

    'Check if Valid Base64
    If Base64EncodeDecodeImage.ValidBase64(base) Then
        ImageView1.Bitmap = Base64EncodeDecodeImage.Base64StringToImage(base)
    End If

    Sleep(2000)

    'Convert without Dir / File as request #8
    Dim bitmap1 As B4XBitmap = ImageView1.Bitmap
    Dim base As String = Base64EncodeDecodeImage.Base64ImageToString2(bitmap1)
    ImageView2.Bitmap = Base64EncodeDecodeImage.Base64StringToImage(base)

    'Any File to Encode64
    Dim pdf_base64 As String = Base64EncodeDecodeImage.Base64AnyFileToString(File.DirApp, "example_5_pages.pdf")
   
    'Check if Valid Base64
    If Base64EncodeDecodeImage.ValidBase64(pdf_base64) Then
       Base64EncodeDecodeImage.Base64StringToAnyFile(pdf_base64, File.DirApp, "convert.pdf")
    End If

Example Code B4A --> https://www.dropbox.com/s/mohtg21cnfvaj1p/CONVERTBMPTOCODE64B4.zip?dl=0
Example Code B4i --> https://www.dropbox.com/s/97x5hcexy9xgkm6/CONVERTBMPTOCODE64.zip?dl=0
Example Code B4J -->https://www.dropbox.com/s/888ic5l1m18f4d1/B4J-CONVERTBMPTOCODE64.zip?dl=0

In attachment library b4xlib
Have a nice day
Marco

18.04.2021
Rel. 1.13 --> Add Base64AnyFileToString
 

Attachments

  • Base64EncodeDecodeImage.b4xlib
    1.5 KB · Views: 961
Last edited:

LucaMs

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Very useful, Marco, thank you.

Since I wanted a second method to "import" a bitmap in your Base64ImageToString, which reads an image file
(I "needed" to pass it a B4XBitmap), I added it but I also took the opportunity to change something.
If you "like" my changes you can add this version to your first post and I will remove this one ;)

Description of changes:
B4X:
' Base64EcondeDecodeImage - Code module
' Author:    MarcoRome

#Region VERSIONS
' 1.1
'    Added ImageToString method, which is identical to Base64ImageToString,
'        but its name is more "correct". Kept Base64ImageToString for backward compatibility.
'    Added ImageToString2 method, which requires a B4XBitmap parameter.
'    Renamed variable name "convert" to mStringUtils
'        and declared it as Private in Process_Globals.
'    Added B4XBitmapToBytes private method - used by ImageToString2.
'    Added some Regions.
' 1.0
#End Region
 

Attachments

  • Base64EncodeDecodeImage.b4xlib
    1.3 KB · Views: 536
Last edited:

By-Cod3rs

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Hello, I want to flip a picture taken from the camera without saving
can you improve it?
thanks.
 

MarcoRome

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I want to convert an unregistered bitmap object or a picture in imageview to base64 format.

Without the picture way.
Look first post

B4X:
'Image to Encode64
Dim base As String = Base64EncodeDecodeImage.Base64ImageToString(Directory,File")
 

By-Cod3rs

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Dim img As Bitmap=ImageView1.Bitmap

Dim base As String = Base64EncodeDecodeImage.Base64ImageToString(img)
I wanted to explain this.thanks
an image where I don't know the path to the file.
 

MarcoRome

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Dim img As Bitmap=ImageView1.Bitmap

Dim base As String = Base64EncodeDecodeImage.Base64ImageToString(img)
I wanted to explain this.thanks
an image where I don't know the path to the file.

In attachment Rel 1.10
 

MarcoRome

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Return Type Byte array :(
Can't String Return Type?
thanks.

As in example 1# Post
B4X:
 'Convert without Dir / File as request #8
    Dim bitmap1 As B4XBitmap = ImageView1.Bitmap
    Dim base As String = Base64EncodeDecodeImage.Base64ImageToString2(bitmap1)
    ImageView2.Bitmap = Base64EncodeDecodeImage.Base64StringToImage(base)
 

By-Cod3rs

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As in example 1# Post
B4X:
 'Convert without Dir / File as request #8
    Dim bitmap1 As B4XBitmap = ImageView1.Bitmap
    Dim base As String = Base64EncodeDecodeImage.Base64ImageToString2(bitmap1)
    ImageView2.Bitmap = Base64EncodeDecodeImage.Base64StringToImage(base)
I just saw it Thank you. Thank you very much
 

By-Cod3rs

Member
Licensed User
I have a problem. I have a .net web Service that meets this picture.
and it doesn't work compatible with its library.
I want to translate the picture into text on mobile and decode the code on the website. What Do You Recommend?
 

MarcoRome

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Its posible to use this lib. in order to encode in base64 any binary file?

thanks

No. But you can use this ( not tested ):

B4X:
Sub Base64AnyFileToString(Dir As String, Filename As String) As String
    Dim convert As StringUtils
    Return convert.EncodeBase64(Bit.InputStreamToBytes(File.OpenInput(Dir, Filename)))
End Sub

Sub Base64StringToAnyFile(s As String, Dir As String , FileName As String)
    Dim su As StringUtils
    Dim bytes() As Byte = su.DecodeBase64(s)
    Dim out As OutputStream = File.OpenOutput(Dir, FileName, False)
    out.WriteBytes(bytes, 0, bytes.Length)
    out.Close
End Sub
 

By-Cod3rs

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It is even simpler as you can use File.ReadBytes / WriteBytes
B4X:
Dim su As StringUtils
Dim base64 As String = su.EncodeBase64(File.ReadBytes(...))

Thanks Erel.
I Solved That Way.
MarcoRome ibrary not supported in .net base64 function.

Snapshot:
Sub Camera1_PictureTaken (Data() As Byte)
'
    Dim su As StringUtils
    Dim base64 As String = su.EncodeBase64(Data)
    Log(base64) 'limit 4000 char..

End Sub


Thus, the picture was displayed on both .net and web.
.Net Base64 Code(:
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Try
            Dim Base64Code As String = "......................................"

            Dim imageBytes As Byte() = Convert.FromBase64String(Base64Code)
            Dim ms As New MemoryStream(imageBytes, 0, imageBytes.Length)
            Dim Btmp As New Bitmap(Image.FromStream(ms))
            PictureBox1.Image = (OrientateImage(Btmp))


        Catch ex As Exception
            MsgBox(ex.Message)
        End Try


    End Sub

    Public Function OrientateImage(img As Image) As Image
        Const EXIF_ORIENTATION = 274
        Dim orientationTag = img.PropertyItems.FirstOrDefault(Function(x) x.Id = EXIF_ORIENTATION)
        If orientationTag IsNot Nothing Then
            Dim orientation As Short = BitConverter.ToInt16(orientationTag.Value, 0)
            Select Case orientation
                Case 3
                    img.RotateFlip(RotateFlipType.Rotate180FlipNone)
                Case 6
                    img.RotateFlip(RotateFlipType.Rotate90FlipNone)
                Case 8
                    img.RotateFlip(RotateFlipType.Rotate270FlipNone)
                Case Else
            End Select
        End If

        Return img
    End Function
 
Last edited:

MarcoRome

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Thanks Erel.
I Solved That Way.
MarcoRome ibrary not supported in .net base64 function.

Snapshot:
Sub Camera1_PictureTaken (Data() As Byte)
'
    Dim su As StringUtils
    Dim base64 As String = su.EncodeBase64(Data)
    Log(base64) 'limit 4000 char..

End Sub


Thus, the picture was displayed on both .net and web.
.Net Base64 Code(:
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Try
            Dim Base64Code As String = "......................................"

            Dim imageBytes As Byte() = Convert.FromBase64String(Base64Code)
            Dim ms As New MemoryStream(imageBytes, 0, imageBytes.Length)
            Dim Btmp As New Bitmap(Image.FromStream(ms))
            PictureBox1.Image = (OrientateImage(Btmp))


        Catch ex As Exception
            MsgBox(ex.Message)
        End Try


    End Sub

    Public Function OrientateImage(img As Image) As Image
        Const EXIF_ORIENTATION = 274
        Dim orientationTag = img.PropertyItems.FirstOrDefault(Function(x) x.Id = EXIF_ORIENTATION)
        If orientationTag IsNot Nothing Then
            Dim orientation As Short = BitConverter.ToInt16(orientationTag.Value, 0)
            Select Case orientation
                Case 3
                    img.RotateFlip(RotateFlipType.Rotate180FlipNone)
                Case 6
                    img.RotateFlip(RotateFlipType.Rotate90FlipNone)
                Case 8
                    img.RotateFlip(RotateFlipType.Rotate270FlipNone)
                Case Else
            End Select
        End If

        Return img
    End Function
Strain, because if you resolved with suggestion by Erel. The library use the same function su.EncodeBase64....
 

MarcoRome

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The library is in new format b4xlib. So if you open the libraries you can see ( and modified ) code without problem.
 
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