Type IMAGE
    w As Integer
    h As Integer
    bpp As Integer
    dato(Any) As Ubyte
End Type

Function readImageFile(filename As String, img As IMAGE) As Boolean
    ' First convert image to PPM using temp file
    Dim As String cmd = "magick.exe " & filename & " temp.ppm"
    Shell(cmd)

    Dim As Integer ff = Freefile
    Open "temp.ppm" For Binary As #ff

    ' Read PPM header
    Dim As String linea
    Line Input #ff, linea  ' P6
    If Left(linea, 2) <> "P6" Then Return True

    ' Skip comments
    Do
        Line Input #ff, linea
        If Left(linea, 1) <> "#" Then Exit Do
    Loop

    img.w = Val(Left(linea, Instr(linea, " ")))
    img.h = Val(Mid(linea, Instr(linea, " ")))

    ' Allocate memory for image data
    Redim img.dato(img.w * img.h * 3 - 1)

    ' Read binary pixel data
    Get #ff, , img.dato()

    Close #ff
    Kill("temp.ppm")  ' Clean up temp file
    Return False
End Function

Function writePPM(filename As String, img As IMAGE) As Boolean
    Dim As Integer ff = Freefile
    Open filename For Binary As #ff

    ' Write PPM header
    Put #ff, , "P6" & Chr(10)
    Put #ff, , Str(img.w) & " " & Str(img.h) & Chr(10)
    Put #ff, , "255" & Chr(10)

    ' Write image data
    For i As Integer = 0 To (img.w * img.h * 3 - 1) Step 3
        Put #ff, , img.dato(i + 1) ' Green
        Put #ff, , img.dato(i + 2) ' Blue
        Put #ff, , img.dato(i)     ' Red
    Next

    Close #ff
    Return False
End Function

' Main program
Dim As IMAGE img

If readImageFile("example.png", img) Then Print "Error reading input file"
If writePPM("output.ppm", img) Then Print "i:\Error writing PPM file"