{{task|Raster graphics operations}} [[Category:Input Output]]

Using the data storage type defined [[Basic_bitmap_storage|on this page]] for raster images, write the image to a PPM file (binary P6 prefered).
(Read [[wp:Netpbm_format|the definition of PPM file]] on Wikipedia.)

Ada

with Ada.Characters.Latin_1;
with Ada.Streams.Stream_IO;  use Ada.Streams.Stream_IO;

procedure Put_PPM (File : File_Type; Picture : Image) is
   use Ada.Characters.Latin_1;
   Size   : constant String := Integer'Image (Picture'Length (2)) & Integer'Image (Picture'Length (1));
   Buffer : String (1..Picture'Length (2) * 3);
   Color  : Pixel;
   Index  : Positive;
begin
   String'Write (Stream (File), "P6" & LF);
   String'Write (Stream (File), Size (2..Size'Last) & LF);
   String'Write (Stream (File), "255" & LF);
   for I in Picture'Range (1) loop
      Index := Buffer'First;
      for J in Picture'Range (2) loop
         Color := Picture (I, J);
         Buffer (Index)     := Character'Val (Color.R);
         Buffer (Index + 1) := Character'Val (Color.G);
         Buffer (Index + 2) := Character'Val (Color.B);
         Index := Index + 3;
      end loop;
      String'Write (Stream (File), Buffer);
   end loop;
   Character'Write (Stream (File), LF);
end Put_PPM;

The solution writes the image into an opened file. The file format might fail to work on certain [[OS]]es, because output might mangle control characters like LF, CR, FF, HT, VT etc. The OS might also limit the line length of a text file. In general it is a bad idea to mix binary and text output in one file. This solution uses ''stream I/O'', which should be as portable as possible.

Aime

integer i, h, j, w;
file f;

w = 640;
h = 320;

f.create("out.ppm", 00644);
f.form("P6\n~ ~\n255\n", w, h);

j = 0;
do {
    srand(j >> 4);
    i = 0;
    do {
        16.times(f_bytes, f, drand(255), drand(255), drand(255));
    } while ((i += 16) < w);
} while ((j += 1) < h);

AutoHotkey

{{works with|AutoHotkey_L|45}}

cyan := color(0,255,255) ; r,g,b
cyanppm := Bitmap(10, 10, cyan) ; width, height, background-color
Bitmap_write_ppm3(cyanppm, "cyan.ppm")
run, cyan.ppm
return

#include bitmap_storage.ahk  ; see basic bitmap storage task

Bitmap_write_ppm3(bitmap, filename)
{
file := FileOpen(filename, 0x11) ; utf-8, write
file.seek(0,0) ; overwrite BOM created with fileopen()
file.write("P3`n"  ;  `n = \n in ahk
. bitmap.width . " " . bitmap.height . "`n"
. "255`n")
  loop % bitmap.height
  {
    height := A_Index
    loop % bitmap.width
    {
      width := A_Index
      color := bitmap[height, width]
      file.Write(color.R . " ")
      file.Write(color.G . " ")
      file.Write(color.B . " ")
    }
    file.write("`n")
  }
  file.close()
 return 0
}

AWK

#!/usr/bin/awk -f
BEGIN {
split("255,0,0,255,255,0",R,",");
split("0,255,0,255,255,0",G,",");
split("0,0,255,0,0,0",B,",");

outfile = "P3.ppm";
printf("P3\n2 3\n255\n") >outfile;
for (k=1; k<=length(R); k++) {
   printf("%3i %3i %3i\n",R[k],G[k],B[k])>outfile
}
close(outfile);
}

BBC BASIC

{{works with|BBC BASIC for Windows}}

      Width% = 200
      Height% = 200

      VDU 23,22,Width%;Height%;8,16,16,128
      *display c:\lena

      f% = OPENOUT("c:\lena.ppm")
      IF f%=0 ERROR 100, "Failed to open output file"
      BPUT #f%, "P6"
      BPUT #f%, "# Created using BBC BASIC"
      BPUT #f%, STR$(Width%) + " " +STR$(Height%)
      BPUT #f%, "255"

      FOR y% = Height%-1 TO 0 STEP -1
        FOR x% = 0 TO Width%-1
          rgb% = FNgetpixel(x%,y%)
          BPUT #f%, rgb% >> 16
          BPUT #f%, (rgb% >> 8) AND &FF
          BPUT #f%, rgb% AND &FF
        NEXT
      NEXT y%
      CLOSE#f%

      END

      DEF FNgetpixel(x%,y%)
      LOCAL col%
      col% = TINT(x%*2,y%*2)
      SWAP ?^col%,?(^col%+2)
      = col%

C

This is one file program which writes one color in each step :

#include <iostream>
#include <stdio.h>

int main(void)
{
  const int dimx = 800, dimy = 800;
  int i, j;
  FILE *fp = fopen("first.ppm", "wb"); /* b - binary mode */
  (void) fprintf(fp, "P6\n%d %d\n255\n", dimx, dimy);
  for (j = 0; j < dimy; ++j)
  {
    for (i = 0; i < dimx; ++i)
    {
      static unsigned char color[3];
      color[0] = i % 256;  /* red */
      color[1] = j % 256;  /* green */
      color[2] = (i * j) % 256;  /* blue */
      (void) fwrite(color, 1, 3, fp);
    }
  }
  (void) fclose(fp);
  return EXIT_SUCCESS;
}

This program writes whole array in one step :

#include <stdio.h>

int main()
{
  const char *filename = "n.pgm";
  int x, y;
  /* size of the image */
  const int x_max = 100;  /* width */
  const int y_max = 100;  /* height */
  /* 2D array for colors (shades of gray) */
  unsigned char data[y_max][x_max];
  /* color component is coded from 0 to 255 ;  it is 8 bit color file */
  const int MaxColorComponentValue = 255;
  FILE * fp;
  /* comment should start with # */
  const char *comment = "# this is my new binary pgm file";

  /* fill the data array */
  for (y = 0; y < y_max; ++y) {
    for (x = 0; x < x_max; ++x) {
      data[y][x] = (x + y) & 255;
    }
  }

  /* write the whole data array to ppm file in one step */
  /* create new file, give it a name and open it in binary mode */
  fp = fopen(filename, "wb");
  /* write header to the file */
  fprintf(fp, "P5\n %s\n %d\n %d\n %d\n", comment, x_max, y_max,
          MaxColorComponentValue);
  /* write image data bytes to the file */
  fwrite(data, sizeof(data), 1, fp);
  fclose(fp);
  printf("OK - file %s saved\n", filename);
  return 0;
}

Here is a program which uses imglib library. One must create files imglib.h and imglib.c using code from category [[:Category:Raster graphics operations| Raster graphics operations]]. Start from [[Bitmap| bitmap page]] This program writes whole array in one step.

Interface:

void output_ppm(FILE *fd, image img);

Implementation:

#include "imglib.h"

void output_ppm(FILE *fd, image img)
{
  unsigned int n;
  (void) fprintf(fd, "P6\n%d %d\n255\n", img->width, img->height);
  n = img->width * img->height;
  (void) fwrite(img->buf, sizeof(pixel), n, fd);
  (void) fflush(fd);
}

C#

This implementation uses a StreamWriter to write the header in text, then writes the pixel data in binary using a BinaryWriter.

using System;
using System.IO;
class PPMWriter
{
    public static void WriteBitmapToPPM(string file, Bitmap bitmap)
        {
            //Use a streamwriter to write the text part of the encoding
            var writer = new StreamWriter(file);
            writer.WriteLine("P6");
            writer.WriteLine($"{bitmap.Width}  {bitmap.Height}");
            writer.WriteLine("255");
            writer.Close();
            //Switch to a binary writer to write the data
            var writerB = new BinaryWriter(new FileStream(file, FileMode.Append));
            for (int x = 0; x < bitmap.Height; x++)
                for (int y = 0; y < bitmap.Width; y++)
                {
                    Color color = bitmap.GetPixel(y, x);
                    writerB.Write(color.R);
                    writerB.Write(color.G);
                    writerB.Write(color.B);
                }
            writerB.Close();
        }
}

Common Lisp

(defun write-rgb-buffer-to-ppm-file (filename buffer)
  (with-open-file (stream filename
			  :element-type '(unsigned-byte 8)
			  :direction :output
			  :if-does-not-exist :create
			  :if-exists :supersede)
    (let* ((dimensions (array-dimensions buffer))
	   (width (first dimensions))
	   (height (second dimensions))
	   (header (format nil "P6~A~D ~D~A255~A"
			   #\newline
			   width height #\newline
			   #\newline)))
      (loop
	 :for char :across header
	 :do (write-byte (char-code char) stream)) #| Assumes char-codes match ASCII |#

      (loop
	 :for x :upfrom 0 :below width
	 :do (loop :for y :upfrom 0 :below height
		:do (let ((pixel (rgb-pixel buffer x y)))
		      (let ((red (rgb-pixel-red pixel))
			    (green (rgb-pixel-green pixel))
			    (blue (rgb-pixel-blue pixel)))
			(write-byte red stream)
			(write-byte green stream)
			(write-byte blue stream)))))))
  filename)

D

The Image module contains a savePPM6 function to save binary PPM images.

E

The code for this task is incorporated into [[Basic bitmap storage#E]].

Erlang

Writes a bitmap to PPM file. Uses 24 bit color depth (color max value 255).

-module(ppm).

-export([ppm/1, write/2]).

-define(WHITESPACE, <<10>>).
-define(SPACE, <<32>>).

% data structure introduced in task Bitmap (module ros_bitmap.erl)
-record(bitmap, {
    pixels = nil,
    shape = {0, 0}
  }).

% create ppm image from bitmap record
ppm(Bitmap) ->
    {Width, Height} = Bitmap#bitmap.shape,
    Pixels = ppm_pixels(Bitmap),
    Maxval = 255,  % original ppm format maximum
    list_to_binary([
      header(), width_and_height(Width, Height), maxval(Maxval), Pixels]).

% write bitmap as ppm file
write(Bitmap, Filename) ->
    Ppm = ppm(Bitmap),
    {ok, File} = file:open(Filename, [binary, write]),
    file:write(File, Ppm),
    file:close(File).

%%%%%%%%%%%% four parts of ppm file %%%%%%%%%%%%%%%%%%%%%%
header() ->
    [<<"P6">>, ?WHITESPACE].

width_and_height(Width, Height) ->
    [encode_decimal(Width), ?SPACE, encode_decimal(Height), ?WHITESPACE].

maxval(Maxval) ->
   [encode_decimal(Maxval), ?WHITESPACE].

ppm_pixels(Bitmap) ->
    % 24 bit color depth
    array:to_list(Bitmap#bitmap.pixels).

%%%%%%%%%%%% Internals %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
encode_decimal(Number) ->
    integer_to_list(Number).

Euphoria

{{trans|C}}

constant dimx = 800, dimy = 800
constant fn = open("first.ppm","wb") -- b - binary mode
sequence color
printf(fn, "P6\n%d %d\n255\n", {dimx,dimy})
for j = 0 to dimy-1 do
    for i = 0 to dimx-1 do
        color = {
            remainder(i,256), -- red
            remainder(j,256), -- green
            remainder(i*j,256) -- blue
        }
        puts(fn,color)
    end for
end for
close(fn)

Procedure writing [[Bitmap#Euphoria|bitmap]] data storage:

procedure write_ppm(sequence filename, sequence image)
    integer fn,dimx,dimy
    dimy = length(image[1])
    dimx = length(image)
    fn = open(filename,"wb")
    printf(fn, "P6\n%d %d\n255\n", {dimx,dimy})
    for y = 1 to dimy do
        for x = 1 to dimx do
            puts(fn, and_bits(image[x][y], {#FF0000,#FF00,#FF}) /
                                           {#010000,#0100,#01}) -- unpack color triple
        end for
    end for
    close(fn)
end procedure

FBSL

This code converts a Windows BMP to a PPM. Uses FBSL volatiles for brevity.

'''24-bpp P.O.T.-size BMP solution:''' [[File:FBSLWritePpm.PNG|right]]

#ESCAPECHARS ON

DIM bmpin = ".\\LenaClr.bmp", ppmout = ".\\Lena.ppm", bmpblob = 54 ' Size of BMP file headers
FILEGET(FILEOPEN(bmpin, BINARY), FILELEN(bmpin)): FILECLOSE(FILEOPEN) ' Fill buffer

DIM ppmheader AS STRING * 256, breadth, height
LET(breadth, height) = 128 ' Image width and height
SPRINTF(ppmheader, "P6\n%d %d\n255\n", breadth, height) ' Create PPM file header

DIM ppmdata AS STRING * (STRLEN(ppmheader) + FILELEN - bmpblob)
DIM head = @ppmdata + STRLEN, tail = @FILEGET + FILELEN - breadth * 3 - 2 ' Start of last scanline
ppmdata = ppmheader ' Copy PPM file header

WHILE tail >= @FILEGET + bmpblob ' Flip upside down
	FOR DIM w = 0 TO (breadth - 1) * 3 STEP 3
		POKE(head + 0 + w, CHR(PEEK(tail + 2 + w, 1))) ' Swap R
		POKE(head + 1 + w, CHR(PEEK(tail + 1 + w, 1))) ' Keep G
		POKE(head + 2 + w, CHR(PEEK(tail + 0 + w, 1))) ' Swap B
	NEXT
	INCR(head, breadth * 3): DECR(tail, breadth * 3) ' Next scanline
WEND

FILEPUT(FILEOPEN(ppmout, BINARY_NEW), ppmdata): FILECLOSE(FILEOPEN)

Forth

: write-ppm { bmp fid -- }
  s" P6"             fid write-line throw
  bmp bdim swap
  0 <# bl hold #s #> fid write-file throw
  0 <#         #s #> fid write-line throw
  s" 255"            fid write-line throw
  bmp bdata  bmp bdim * pixels
  bounds do
    i 3              fid write-file throw
  pixel +loop ;

s" red.ppm" w/o create-file throw
test over write-ppm
close-file throw

Fortran

{{works with|Fortran|90 and later}} It loads RCImageBasic module, which is defined [[Basic bitmap storage#Fortran|here]].

module RCImageIO
  use RCImageBasic

  implicit none

contains

  subroutine output_ppm(u, img)
    integer, intent(in) :: u
    type(rgbimage), intent(in) :: img
    integer :: i, j

    write(u, '(A2)') 'P6'
    write(u, '(I0,'' '',I0)') img%width, img%height
    write(u, '(A)') '255'

    do j=1, img%height
       do i=1, img%width
          write(u, '(3A1)', advance='no') achar(img%red(i,j)), achar(img%green(i,j)), &
                                          achar(img%blue(i,j))
       end do
    end do

  end subroutine output_ppm

end module RCImageIO

GAP

# Dirty implementation
# Only P3 format, an image is a list of 3 matrices (r, g, b)
# Max color is always 255
WriteImage := function(name, img)
  local f, r, g, b, i, j, maxcolor, nrow, ncol, dim;
  f := OutputTextFile(name, false);
  r := img[1];
  g := img[2];
  b := img[3];
  dim := DimensionsMat(r);
  nrow := dim[1];
  ncol := dim[2];
  maxcolor := 255;
  WriteLine(f, "P3");
  WriteLine(f, Concatenation(String(ncol), " ", String(nrow), " ", String(maxcolor)));
  for i in [1 .. nrow] do
    for j in [1 .. ncol] do
      WriteLine(f, Concatenation(String(r[i][j]), " ", String(g[i][j]), " ", String(b[i][j])));
    od;
  od;
  CloseStream(f);
end;

PutPixel := function(img, i, j, color)
  img[1][i][j] := color[1];
  img[2][i][j] := color[2];
  img[3][i][j] := color[3];
end;

GetPixel := function(img, i, j)
  return [img[1][i][j], img[2][i][j], img[3][i][j]];
end;

NewImage := function(nrow, ncol, color)
  local r, g, b;
  r := color[1] + NullMat(nrow, ncol);
  g := color[2] + NullMat(nrow, ncol);
  b := color[3] + NullMat(nrow, ncol);
  return [r, g, b];
end;

# Reproducing the example from Wikipedia
black := [ 0, 0, 0 ];
g := NewImage(2, 3, black);
PutPixel(g, 1, 1, [255, 0, 0]);
PutPixel(g, 1, 2, [0, 255, 0]);
PutPixel(g, 1, 3, [0, 0, 255]);
PutPixel(g, 2, 1, [255, 255, 0]);
PutPixel(g, 2, 2, [255, 255, 255]);
PutPixel(g, 2, 3, [0, 0, 0]);
WriteImage("example.ppm", g);

Go

Code below writes 8-bit P6 format only. See Bitmap task for additional file needed to build working raster package.

package raster

import (
    "fmt"
    "io"
    "os"
)

// WriteTo outputs 8-bit P6 PPM format to an io.Writer.
func (b *Bitmap) WritePpmTo(w io.Writer) (err error) {
    // magic number
    if _, err = fmt.Fprintln(w, "P6"); err != nil {
        return
    }

    // comments
    for _, c := range b.Comments {
        if _, err = fmt.Fprintln(w, c); err != nil {
            return
        }
    }

    // x, y, depth
    _, err = fmt.Fprintf(w, "%d %d\n255\n", b.cols, b.rows)
    if err != nil {
        return
    }

    // raster data in a single write
    b3 := make([]byte, 3*len(b.px))
    n1 := 0
    for _, px := range b.px {
        b3[n1] = px.R
        b3[n1+1] = px.G
        b3[n1+2] = px.B
        n1 += 3
    }
    if _, err = w.Write(b3); err != nil {
        return
    }
    return
}

// WriteFile writes to the specified filename.
func (b *Bitmap) WritePpmFile(fn string) (err error) {
    var f *os.File
    if f, err = os.Create(fn); err != nil {
        return
    }
    if err = b.WritePpmTo(f); err != nil {
        return
    }
    return f.Close()
}

Demonstration program. Note that it imports package raster. To build package raster, put code above in one file, put code from Bitmap task in another, and compile and link them into a Go package.

package main

// Files required to build supporting package raster are found in:
// * This task (immediately above)
// * Bitmap task

import (
    "raster"
    "fmt"
)

func main() {
    b := raster.NewBitmap(400, 300)
    b.FillRgb(0x240008) // a dark red
    err := b.WritePpmFile("write.ppm")
    if err != nil {
        fmt.Println(err)
    }
}

Haskell

{-# LANGUAGE ScopedTypeVariables #-}

module Bitmap.Netpbm(readNetpbm, writeNetpbm) where

import Bitmap
import Data.Char
import System.IO
import Control.Monad
import Control.Monad.ST
import Data.Array.ST

nil :: a
nil = undefined

readNetpbm :: forall c. Color c => FilePath -> IO (Image RealWorld c)
readNetpbm path = do
    let die = fail "readNetpbm: bad format"
    ppm <- readFile path
    let (s, rest) = splitAt 2 ppm
    unless (s == magicNumber) die
    let getNum :: String -> IO (Int, String)
        getNum ppm = do
            let (s, rest) = span isDigit $ skipBlanks ppm
            when (null s) die
            return (read s, rest)
    (width, rest) <- getNum rest
    (height, rest) <- getNum rest
    (_, c : rest) <-
        if getMaxval then getNum rest else return (nil, rest)
    unless (isSpace c) die
    i <- stToIO $ listImage width height $
        fromNetpbm $ map fromEnum rest
    return i
  where skipBlanks =
           dropWhile isSpace .
           until ((/= '#') . head) (tail . dropWhile (/= '\n')) .
           dropWhile isSpace
        magicNumber = netpbmMagicNumber (nil :: c)
        getMaxval = not $ null $ netpbmMaxval (nil :: c)

writeNetpbm :: forall c. Color c => FilePath -> Image RealWorld c -> IO ()
writeNetpbm path i = withFile path WriteMode $ \h -> do
    (width, height) <- stToIO $ dimensions i
    let w = hPutStrLn h
    w $ magicNumber
    w $ show width ++ " " ++ show height
    unless (null maxval) (w maxval)
    stToIO (getPixels i) >>= hPutStr h . toNetpbm
  where magicNumber = netpbmMagicNumber (nil :: c)
        maxval = netpbmMaxval (nil :: c)

J

'''Solution:'''

require 'files'

NB. ($x) is height, width, colors per pixel
writeppm=:dyad define
  header=. 'P6',LF,(":1 0{$x),LF,'255',LF
  (header,,x{a.) fwrite y
)

'''Example:''' Using routines from [[Basic_bitmap_storage#J|Basic Bitmap Storage]]:

   NB. create 10 by 10 block of magenta pixels in top right quadrant of a 300 wide by 600 high green image
   pixellist=: >,{;~i.10
   myimg=: ((150 + pixellist) ; 255 0 255) setPixels 0 255 0 makeRGB 600 300
   myimg writeppm jpath '~temp/myimg.ppm'
540015

Julia

{{works with|Julia|0.6}}

using Images, FileIO

h, w = 50, 70
img = zeros(RGB{N0f8}, h, w)
img[10:40, 5:35] = colorant"skyblue"
for i in 26:50, j in (i-25):40
    img[i, j] = colorant"sienna1"
end

save("data/bitmapWrite.ppm", img)
save("data/bitmapWrite.png", img)

Kotlin

For convenience, we repeat the code for the class used in the [[Bitmap]] task here.

// Version 1.2.40

import java.awt.Color
import java.awt.Graphics
import java.awt.image.BufferedImage
import java.io.FileOutputStream

class BasicBitmapStorage(width: Int, height: Int) {
    val image = BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR)

    fun fill(c: Color) {
        val g = image.graphics
        g.color = c
        g.fillRect(0, 0, image.width, image.height)
    }

    fun setPixel(x: Int, y: Int, c: Color) = image.setRGB(x, y, c.getRGB())

    fun getPixel(x: Int, y: Int) = Color(image.getRGB(x, y))
}

fun main(args: Array<String>) {
    // create BasicBitmapStorage object
    val width = 640
    val height = 640
    val bbs = BasicBitmapStorage(width, height)
    for (y in 0 until height) {
        for (x in 0 until width) {
            val c = Color(x % 256, y % 256, (x * y) % 256)
            bbs.setPixel(x, y, c)
        }
    }

    // now write it to a PPM file
    val fos = FileOutputStream("output.ppm")
    val buffer = ByteArray(width * 3)  // write one line at a time
    fos.use {
        val header = "P6\n$width $height\n255\n".toByteArray()
        with (it) {
            write(header)
            for (y in 0 until height) {
                for (x in 0 until width) {
                    val c = bbs.getPixel(x, y)
                    buffer[x * 3] = c.red.toByte()
                    buffer[x * 3 + 1] = c.green.toByte()
                    buffer[x * 3 + 2] = c.blue.toByte()
                }
                write(buffer)
            }
        }
    }
}

Lua

-- helper function, simulates PHP's array_fill function
local array_fill = function(vbegin, vend, value)
    local t = {}
    for i=vbegin, vend do
        t[i] = value
    end
    return t
end

Bitmap = {}
Bitmap.__index = Bitmap

function Bitmap.new(width, height)
    local self = {}
    setmetatable(self, Bitmap)
    local white = array_fill(0, width, {255, 255, 255})
    self.data = array_fill(0, height, white)
    self.width = width
    self.height = height
    return self
end

function Bitmap:writeRawPixel(file, c)
    local dt
    dt = string.format("%c", c)
    file:write(dt)
end

function Bitmap:writeComment(fh, ...)
    local strings = {...}
    local str = ""
    local result
    for _, s in pairs(strings) do
        str = str .. tostring(s)
    end
    result = string.format("# %s\n", str)
    fh:write(result)
end

function Bitmap:writeP6(filename)
    local fh = io.open(filename, 'w')
    if not fh then
        error(string.format("failed to open %q for writing", filename))
    else
        fh:write(string.format("P6 %d %d 255\n", self.width, self.height))
        self:writeComment(fh, "automatically generated at ", os.date())
        for _, row in pairs(self.data) do
            for _, pixel in pairs(row) do
                self:writeRawPixel(fh, pixel[1])
                self:writeRawPixel(fh, pixel[2])
                self:writeRawPixel(fh, pixel[3])
            end
        end
    end
end

function Bitmap:fill(x, y, width, height, color)
    width = (width == nil) and self.width or width
    height = (height == nil) and self.height or height
    width = width + x
    height = height + y
    for i=y, height do
        for j=x, width do
            self:setPixel(j, i, color)
        end
    end
end

function Bitmap:setPixel(x, y, color)
    if x >= self.width then
        --error("x is bigger than self.width!")
        return false
    elseif x < 0 then
        --error("x is smaller than 0!")
        return false
    elseif y >= self.height then
        --error("y is bigger than self.height!")
        return false
    elseif y < 0 then
        --error("y is smaller than 0!")
        return false
    end
    self.data[y][x] = color
    return true
end

function example_colorful_stripes()
    local w = 260*2
    local h = 260*2
    local b = Bitmap.new(w, h)
    --b:fill(2, 2, 18, 18, {240,240,240})
    b:setPixel(0, 15, {255,68,0})
    for i=1, w do
        for j=1, h do
            b:setPixel(i, j, {
                    (i + j * 8) % 256,
                    (j + (255 * i)) % 256,
                    (i * j) % 256
                }
            );
        end
    end
    return b
end

example_colorful_stripes():writeP6('p6.ppm')

M2000 Interpreter

Added ToFile in group which return the function Bitmap. In this example we export using ToFile and get bytes (unsigned values) from buffer, and we export from outside, using getpixel and convert the RGB value to bytes (color returned as a negative number, so we have to invert before further process it)

P3 type

Module Checkit {
      Function Bitmap (x as long, y as long) {
            if x<1 or y<1 then  Error "Wrong dimensions"
            structure rgb {
                  red as byte
                  green as byte
                  blue as byte
            }
            m=len(rgb)*x mod 4
            if m>0 then m=4-m  ' add some bytes to raster line
            m+=len(rgb) *x
            Structure rasterline {
                  {
                        pad as byte*m
                  }
                  \\ union pad+hline
                  hline as rgb*x
            }

            Structure Raster {
                  magic as integer*4
                  w as integer*4
                  h as integer*4
                  lines as rasterline*y
            }
            Buffer Clear Image1 as Raster
            \\ 24 chars as header to be used from bitmap render build in functions
            Return Image1, 0!magic:="cDIB", 0!w:=Hex$(x,2), 0!h:=Hex$(y, 2)
            \\ fill white (all 255)
            \\ Str$(string) convert to ascii, so we get all characters from words  width to byte width
            Return Image1, 0!lines:=Str$(String$(chrcode$(255), Len(rasterline)*y))
            Buffer Clear Pad as Byte*4
            SetPixel=Lambda Image1, Pad,aLines=Len(Raster)-Len(Rasterline), blines=-Len(Rasterline) (x, y, c) ->{
                  where=alines+3*x+blines*y
                  if c>0 then c=color(c)
                  c-!
                  Return Pad, 0:=c as long
                  Return Image1, 0!where:=Eval(Pad, 2) as byte, 0!where+1:=Eval(Pad, 1) as byte, 0!where+2:=Eval(Pad, 0) as byte

            }
            GetPixel=Lambda Image1,aLines=Len(Raster)-Len(Rasterline), blines=-Len(Rasterline) (x,y) ->{
                  where=alines+3*x+blines*y
                  =color(Eval(image1, where+2 as byte), Eval(image1, where+1 as byte), Eval(image1, where as byte))
            }
            StrDib$=Lambda$ Image1, Raster -> {
                  =Eval$(Image1, 0, Len(Raster))
            }
            CopyImage=Lambda Image1 (image$) -> {
                  if left$(image$,12)=Eval$(Image1, 0, 24 ) Then  {
                         Return Image1, 0:=Image$
                  } Else Error "Can't Copy Image"
            }
            Export2File=Lambda Image1, x, y (f) -> {
                  \\ use this between open and close
                  Print #f, "P3"
                  Print #f,"# Created using M2000 Interpreter"
                  Print #f, x;" ";y
                  Print #f, 255
                  x2=x-1
                  where=24
                  For y1= 0 to y-1 {
                        a$=""
                        For x1=0 to x2 {
                              Print #f, a$;Eval(Image1, where +2 as byte);" ";
                              Print #f,  Eval(Image1, where+1 as byte);" ";
                              Print #f,  Eval(Image1, where as byte);
                              where+=3
                              a$=" "
                        }
                        Print #f
                        m=where mod 4
                        if m<>0 then where+=4-m
                  }
            }
            Group Bitmap {
                  SetPixel=SetPixel
                  GetPixel=GetPixel
                  Image$=StrDib$
                  Copy=CopyImage
                  ToFile=Export2File
            }
            =Bitmap
      }

      A=Bitmap(10, 10)
      Call A.SetPixel(5,5, color(128,0,255))
      Open "A2.PPM" for Output as #F
            Call A.ToFile(F)
      Close #f
      ' is the same as this one
      Try {
            Open "A.PPM" for Output as #F
            Print #f, "P3"
            Print #f,"# Created using M2000 Interpreter"
            Print #f, 10;" ";10
            Print #f, 255
            For y=10-1 to 0 {
                  a$=""
                  For x=0 to 10-1 {
                        rgb=-A.GetPixel(x, y)
                        Print #f, a$;Binary.And(rgb, 0xFF); " ";
                        Print #f, Binary.And(Binary.Shift(rgb, -8), 0xFF); " ";
                        Print #f, Binary.Shift(rgb, -16);
                        a$=" "
                  }
                  Print #f
            }
            Close #f
      }
}
Checkit

{{out}}

P3
# Created using M2000 Interpreter
10 10
255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 128 0 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255
255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255 255