B4J Question Image dimension (on disk)

[christiantric]

Hi all,
I load an image from disk via FileChooser in an ImageView in this way:

Dim fc As FileChooser
    fc.Initialize
    fc.Title="Select the work image"
    fc.InitialDirectory = FileSystem.FindUserDocumentsFolder
    fc.SetExtensionFilter("Image", Array As String("*.jpg","*.png","*.bmp"))
    Dim fileChosen As String = fc.ShowOpen(ParentForm)
   
    If fileChosen.Length = 0 Then
        Return
    End If
   
    Dim filePath As String = File.GetFileParent(fileChosen)
    Dim fileName As String = File.GetName(fileChosen)
   
    Dim newImage As Image
    newImage.Initialize(filePath, fileName)
    imgWork.SetImage(newImage)

Later I save the image from ImageView to the disk in this way:

Dim editImage As Image = imgWork.GetImage
If editImage.IsInitialized Then
    File.WriteBytes(filesPath, fileName, ImageUtils.ImageToBytes(editImage))
End If

Public Sub ImageToBytes(img As Image) As Byte()
    Dim out As OutputStream
    out.InitializeToBytesArray(0)
    img.WriteToStream(out)
    out.Close
    Return out.ToBytesArray
End Sub

The dimension of the original file is 1,45MB.
The dimension of the saved file is 10,6MB.

Why the file gets so big?

Christian

 

[OliverA]

According to the documentation (https://www.b4x.com/b4j/help/jfx.html#image_writetostream), Image's WriteToStream produces a PNG, not a JPG. Therefore, the image should be larger (due to lossless compression).
Edit: If the source image happens to be a JPG. If it was a PNG, than good question.

 

[christiantric]

Yes, you could be right because the source image is jpg.
If that's the case, how could I load and save image again keeping the same image quality and dimensions?

 

[OliverA]

Try this: https://www.b4x.com/android/forum/t...byte-array-with-resize-quality-options.91774/
Note: the JPG file format does not store the "quality" setting that was used to save the file. You may need to play with that a bit. Link: https://stackoverflow.com/a/2024971

 

[Harris]

If the image is not modified, why not use File.Copy(2) (Async)...

 

[christiantric]

@OliverA thanks you for the interesting info you pointed me out but what @Harris suggested is enough to solve the problem (due to my incompetence).
Thanks again guys.