dim Current as PictureMBS // global
dim f as FolderItem

f=GetopenFolderItem(FileTypes.Png)

if f<>Nil then
  Current=nil
  
  dim p as new PNGReaderMBS
  
  if p.OpenFile(f) then
    if p.ApplyOptions(0) then
      
      Current=new PictureMBS(p.Width,p.Height,PictureMBS.ImageFormatRGB)
      
      dim i,c as integer
      
      c=p.Height-1
      for i=0 to c
        Current.RowInFormat(i, PictureMBS.ImageFormatRGBA)=p.ReadRow
      next
      
    end if
  end if
end if

dim f as FolderItem = getfolderitem("mbs.png")
dim b as BinaryStream = f.OpenAsBinaryFile(false) // BinaryStream.Open(f) in newer RB versions
dim s as string = b.Read(B.Length)

dim p as new PNGReaderMBS
if p.OpenSpecialData(s) then
  if p.ApplyOptions(0) then
    if p.ReadPicture then
      Backdrop = p.Pict
      Title = "OK"
    else
      Title = "Failed to read picture."
    end if
  else
    Title = "Failed to apply options."
  end if
else
  Title = "Failed to open picture."
end if

dim fSource as FolderItem = SpecialFolder.Desktop.Child("test.png") // some png with alpha
dim oPNGInput as new PNGReaderMBS

If oPNGInput.OpenFile(fSource) Then
  If oPNGInput.ApplyOptions(0) Then
    
    dim imgSource as New PictureMBS(oPNGInput.Width, oPNGInput.Height, PictureMBS.ImageFormatRGBA)
    
    ' Read row by row the file and puts it in a PictureMBS instance
    
    dim nMax as integer = oPNGInput.Height - 1
    For nInd as integer = 0 To nMax
      imgSource.RowInFormat(nInd, PictureMBS.ImageFormatRGBA, true) = oPNGInput.ReadRow()
    Next
    
    ' show only alpha/mask channel
    Backdrop=imgSource.AlphaChannel.CopyPicture
    
    ' show Picture without mask
    Backdrop=imgSource.CopyPicture
    
    ' show picture with mask
    Backdrop=imgSource.CopyPictureWithMask
    
  End If
End If

dim p as PNGReaderMBS // your reader

// write data to file
dim fo as FolderItem = SpecialFolder.Desktop.Child("mbsout.png")
dim bo as BinaryStream = fo.CreateBinaryFile("") // BinaryStream.Create(fo,true) in newer RB Versions

bo.Write p.SourceData

dim p as new PNGReaderMBS
p.SwapRB = true