package main

// Files required to build supporting package raster are found in:
// * This task (immediately above)
// * Bitmap
// * Grayscale image
// * Write a PPM file

import (
    "raster"
    "fmt"
)

func main() {
    // (A file with this name is output by the Go solution to the task
    // "Bitmap/Read an image through a pipe," but of course any 8-bit
    //  P6 PPM file should work.)
    b, err := raster.ReadPpmFile("pipein.ppm")
    if err != nil {
        fmt.Println(err)
        return
    }
    b = b.Grmap().Bitmap()
    err = b.WritePpmFile("grayscale.ppm")
    if err != nil {
        fmt.Println(err)
    }
}