Bitmap/Write a PPM file
From Rosetta Code
< Bitmap
You are encouraged to solve this task according to the task description, using any language you may know.
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Contents |
[edit] 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 OSes, 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.
[edit] AutoHotkey
Works with: AutoHotkey_L version 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
}
[edit] C
Interface:
void output_ppm(FILE *fd, image img);
Implementation:
#include "imglib.h"
void output_ppm(FILE *fd, image img)
{
unsigned int n;
fprintf(fd, "P6\n%d %d\n255\n", img->width, img->height);
n = img->width * img->height;
fwrite(img->buf, sizeof(pixel), n, fd);
fflush(fd);
}
[edit] 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.Write("P6" + Environment.NewLine);
writer.Write(bitmap.Width + " " +bitmap.Height + Environment.NewLine);
writer.Write("255" + Environment.NewLine);
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.Width;x++)
for (int y = 0; y < bitmap.Height; y++)
{
var color = bitmap.GetPixel(x, y);
writerB.Write(color.Red);
writerB.Write(color.Green);
writerB.Write(color.Blue);
}
writerB.Close();
}
}
[edit] 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)
[edit] D
Library: Tango
This describes modifications that needs to be done to class P6Image described on Read ppm file problem page.
Two additional imports are needed:
import tango.io.protocol.Writer;
import tango.io.protocol.model.IWriter;
P6Image will implement IWritable interface
class P6Image : IWritable {
//....
// additional convinient constructor
this(RgbBitmap bitmap, ubyte maxVal) {
this.bitmap = bitmap;
_maxVal = maxVal;
gotImg = 1;
}
// implements tango's IWritable, only one method needed
override
void write (IWriter output)
{
static const char space = ' ';
static const char newline = '\n';
if (! gotImg) throw new NoImageException;
// unfortunatelly, we can't output(type),
// because arrays are prefixed with array length by IWriter
foreach (sign; type) output (sign);
output (newline);
foreach (sign; .toString(bitmap.width)) output (sign);
output (space);
foreach (sign; .toString(bitmap.height)) output (sign);
output (newline);
foreach (sign; .toString(_maxVal)) output (sign);
output (newline);
output.buffer.append(bitmap.data);
output (); // flush
}
}
Saving a file is easy as a pie:
auto p6 = new P6Image(new FileConduit("image.ppm"));
auto write = new Writer(new FileConduit("out.ppm", FileConduit.WriteCreate));
write (p6);
[edit] E
The code for this task is incorporated into Basic bitmap storage#E.
[edit] 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
[edit] Fortran
Works with: Fortran version 90 and later
It loads RCImageBasic module, which is defined 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
[edit] 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)
[edit] 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:
NB. create 10 by 10 block of magenta pixels in top right quadrant of a 300 wide by 600 high green image
myimg=: ((145 + pixellist) ; 255 0 255) setPixels 0 255 0 makeRGB 600 200
myimg writeppm jpath '~temp/myimg.ppm'
360015
[edit] Modula-3
Bitmap is the module from Basic Bitmap Storage.
INTERFACE PPM;
IMPORT Bitmap, Pathname;
PROCEDURE Create(imgfile: Pathname.T; img: Bitmap.T);
END PPM.
MODULE PPM;
IMPORT Bitmap, Wr, FileWr, Pathname;
FROM Fmt IMPORT F, Int;
<*FATAL ANY*>
VAR imgfilewr: FileWr.T;
PROCEDURE Create(imgfile: Pathname.T; img: Bitmap.T) =
VAR height := LAST(img^);
width := LAST(img[0]);
color: Bitmap.Pixel;
BEGIN
imgfilewr := FileWr.Open(imgfile);
Wr.PutText(imgfilewr, F("P6\n%s %s\n255\n", Int(height + 1), Int(width + 1)));
FOR i := 0 TO height DO
FOR j := 0 TO width DO
color := img[i,j];
Wr.PutChar(imgfilewr, VAL(color.R, CHAR));
Wr.PutChar(imgfilewr, VAL(color.G, CHAR));
Wr.PutChar(imgfilewr, VAL(color.B, CHAR));
END;
END;
Wr.PutChar(imgfilewr, '\n');
Wr.Flush(imgfilewr);
END Create;
BEGIN
END PPM.
[edit] OCaml
let output_ppm ~oc ~img:(_, r_channel, g_channel, b_channel) =
let width = Bigarray.Array2.dim1 r_channel
and height = Bigarray.Array2.dim2 r_channel in
Printf.fprintf oc "P6\n%d %d\n255\n" width height;
for y = 0 to pred height do
for x = 0 to pred width do
output_char oc (char_of_int r_channel.{x,y});
output_char oc (char_of_int g_channel.{x,y});
output_char oc (char_of_int b_channel.{x,y});
done;
done;
output_char oc '\n';
flush oc;
;;
[edit] Oz
As a function in the module BitmapIO.oz:
functor
import
Bitmap
Open
export
%% Read
Write
define
%% Omitted: Read
proc {Write B=bitmap(array2d(width:W height:H ...)) Filename}
F = {New Open.file init(name:Filename flags:[write create truncate binary])}
proc {WriteColor8 color(R G B)}
{F write(vs:[R G B])}
end
fun {ToBytes C}
[C div 0x100 C mod 0x100]
end
proc {WriteColor16 color(R G B)}
{F write(vs:{Flatten {Map [R G B] ToBytes}})}
end
MaxCol = {Bitmap.maxValue B}
MaxVal#Writer = if MaxCol =< 0xff then 0xff#WriteColor8
else 0xffff#WriteColor16
end
Header = "P6\n"#W#" "#H#" "#MaxVal#"\n"
in
try
{F write(vs:Header)}
{Bitmap.forAllPixels B Writer}
finally
{F close}
end
end
end
[edit] Perl
Library: Imlib2
Imlib2 can handle several formats, among these JPG, PNG, PNM/PPM... (but it depends on how the Imlib2 was built on the system, since the ability to load or save in these formats depends on other external libraries, like libpng e.g.)
#! /usr/bin/perl
use strict;
use Image::Imlib2;
my $img = Image::Imlib2->new(100,100);
$img->set_color(100,200,0, 255);
$img->fill_rectangle(0,0,100,100);
$img->save("out0.ppm");
$img->save("out0.jpg");
$img->save("out0.png");
exit 0;
Normally Image::Imlib2 understands which output format to use from the extension; to override its guess, you can use:
$img->image_set_format("jpeg"); # or png, tiff, ppm ...
[edit] PHP
Writes a P6 binary file
class Bitmap {
public $data;
public $w;
public $h;
public function __construct($w = 16, $h = 16){
$white = array_fill(0, $w, array(255,255,255));
$this->data = array_fill(0, $h, $white);
$this->w = $w;
$this->h = $h;
}
//Fills a rectangle, or the whole image with black by default
public function fill($x = 0, $y = 0, $w = null, $h = null, $color = array(0,0,0)){
if (is_null($w)) $w = $this->w;
if (is_null($h)) $h = $this->h;
$w += $x;
$h += $y;
for ($i = $y; $i < $h; $i++){
for ($j = $x; $j < $w; $j++){
$this->setPixel($j, $i, $color);
}
}
}
public function setPixel($x, $y, $color = array(0,0,0)){
if ($x >= $this->w) return false;
if ($x < 0) return false;
if ($y >= $this->h) return false;
if ($y < 0) return false;
$this->data[$y][$x] = $color;
}
public function getPixel($x, $y){
return $this->data[$y][$x];
}
public function writeP6($filename){
$fh = fopen($filename, 'w');
if (!$fh) return false;
fputs($fh, "P6 {$this->w} {$this->h} 255\n");
foreach ($this->data as $row){
foreach($row as $pixel){
fputs($fh, pack('C', $pixel[0]));
fputs($fh, pack('C', $pixel[1]));
fputs($fh, pack('C', $pixel[2]));
}
}
fclose($fh);
}
}
$b = new Bitmap(16,16);
$b->fill();
$b->fill(2, 2, 18, 18, array(240,240,240));
$b->setPixel(0, 15, array(255,0,0));
$b->writeP6('p6.ppm');
[edit] PL/I
/* BITMAP FILE: write out a file in PPM format, P6 (binary). 14/5/2010 */
test: procedure options (main);
declare image (0:19,0:19) bit (24);
declare 1 pixel union,
2 color bit (24) aligned,
2 primaries,
3 R character (1),
3 G character (1),
3 B character (1);
declare ch character (1);
declare (i, j) fixed binary;
declare out file record;
open file (out) title ('/IMAGE.PPM,TYPE(FIXED),RECSIZE(1)' ) OUTPUT;
ch = 'P'; write file (out) from (ch);
ch = '6'; write file (out) from (ch);
call put_integer (hbound(image, 1));
call put_integer (hbound(image, 2));
call put_integer (255);
do i = 0 to hbound(image,1);
do j = 0 to hbound(image, 2);
color = image(i,j);
write file (out) from (R);
write file (out) from (G);
write file (out) from (B);
end;
end;
put_integer: procedure (k);
declare k fixed binary;
declare s character (30) varying;
declare i fixed binary;
declare ch character (1);
s = k;
s = trim(s);
do i = 1 to length(s);
ch = substr(s, i, 1);
write file (out) from (ch);
end;
ch = '09'x;
write file (out) from (ch);
end put_integer;
end test;
[edit] PicoLisp
(de ppmWrite (Ppm File)
(out File
(prinl "P6")
(prinl (length (car Ppm)) " " (length Ppm))
(prinl 255)
(for Y Ppm (for X Y (apply wr X))) ) )
[edit] PureBasic
Procedure SaveImageAsPPM(Image, file$, Binary = 1)
; Author Roger Rösch (Nickname Macros)
IDFiIe = CreateFile(#PB_Any, file$)
If IDFiIe
If StartDrawing(ImageOutput(Image))
WriteStringN(IDFiIe, "P" + Str(3 + 3*Binary))
WriteStringN(IDFiIe, "#Created with PureBasic using a Function created from Macros for Rosettacode.org ")
width = ImageWidth(Image)
height = ImageHeight(Image)
WriteStringN(IDFiIe, Str(width) + " " + Str(height))
WriteStringN(IDFiIe, "255")
If Binary = 0
For y = 0 To height - 1
For x = 0 To width - 1
color = Point(x, y)
WriteString(IDFiIe, Str(Red(color)) + " " + Str(Green(color)) + " " + Str(Blue(color)) + " ")
Next
WriteStringN(IDFiIe, "")
Next
Else ; Save in Binary Format
For y = 0 To height - 1
For x = 0 To width - 1
color = Point(x, y)
WriteByte(IDFiIe, Red(color))
WriteByte(IDFiIe, Green(color))
WriteByte(IDFiIe, Blue(color))
Next
Next
EndIf
StopDrawing()
EndIf
CloseFile(IDFiIe)
EndIf
EndProcedure
[edit] Python
Works with: Python version 3.1
Extending the example given here
# String masquerading as ppm file (version P3)
import io
ppmfileout = io.StringIO('')
def writeppmp3(self, f):
self.writeppm(f, ppmformat='P3')
def writeppm(self, f, ppmformat='P6'):
assert ppmformat in ['P3', 'P6'], 'Format wrong'
magic = ppmformat + '\n'
comment = '# generated from Bitmap.writeppm\n'
maxval = max(max(max(bit) for bit in row) for row in self.map)
assert ppmformat == 'P3' or 0 <= maxval < 256, 'R,G,B must fit in a byte'
if ppmformat == 'P6':
fwrite = lambda s: f.write(bytes(s, 'UTF-8'))
maxval = 255
else:
fwrite = f.write
numsize=len(str(maxval))
fwrite(magic)
fwrite(comment)
fwrite('%i %i\n%i\n' % (self.width, self.height, maxval))
for h in range(self.height-1, -1, -1):
for w in range(self.width):
r, g, b = self.get(w, h)
if ppmformat == 'P3':
fwrite(' %*i %*i %*i' % (numsize, r, numsize, g, numsize, b))
else:
fwrite('%c%c%c' % (r, g, b))
if ppmformat == 'P3':
fwrite('\n')
Bitmap.writeppmp3 = writeppmp3
Bitmap.writeppm = writeppm
# Draw something simple
bitmap = Bitmap(4, 4, black)
bitmap.fillrect(1, 0, 1, 2, white)
bitmap.set(3, 3, Colour(127, 0, 63))
# Write to the open 'file' handle
bitmap.writeppmp3(ppmfileout)
# Whats in the generated PPM file
print(ppmfileout.getvalue())
'''
The print statement above produces the following output :
P3
# generated from Bitmap.writeppmp3
4 4
255
0 0 0 0 0 0 0 0 0 127 0 63
0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 255 255 255 0 0 0 0 0 0
0 0 0 255 255 255 0 0 0 0 0 0
'''
# Write a P6 file
ppmfileout = open('tmp.ppm', 'wb')
bitmap.writeppm(ppmfileout)
ppmfileout.close()
[edit] R
Library: pixmap
# View the existing code in the library
library(pixmap)
pixmap::write.pnm
#Usage
write.pnm(theimage, filename)
[edit] Ruby
Extending Basic_bitmap_storage#Ruby
class RGBColour
def values
[@red, @green, @blue]
end
end
class Pixmap
def save(filename)
File.open(filename, 'w') do |f|
f.puts "P6", "#{@width} #{@height}", "255"
f.binmode
@width.times do |x|
@height.times do |y|
f.print @data[x][y].values.pack('C3')
end
end
end
end
alias_method :write, :save
end
[edit] Scheme
Works with: Scheme version R5RS
(define (write-ppm image file)
(define (write-image image)
(define (write-row row)
(define (write-colour colour)
(if (not (null? colour))
(begin (write-char (integer->char (car colour)))
(write-colour (cdr colour)))))
(if (not (null? row))
(begin (write-colour (car row)) (write-row (cdr row)))))
(if (not (null? image))
(begin (write-row (car image)) (write-image (cdr image)))))
(with-output-to-file file
(lambda ()
(begin (display "P6")
(newline)
(display (length (car image)))
(display " ")
(display (length image))
(newline)
(display 255)
(newline)
(write-image image)))))
Example using definitions in Basic bitmap storage#Scheme:
(define image (make-image 800 600))
(image-fill! image *black*)
(image-set! image 400 300 *blue*)
(write-ppm image "out.ppm")
[edit] Tcl
Library: Tk Referring to Basic bitmap storage#Tcl:
package require Tk
proc output_ppm {image filename} {
$image write $filename -format ppm
}
set img [newImage 150 150]
fill $img red
setPixel $img green 40 40
output_ppm $img filename.ppm
# check the file format:
set fh [open filename.ppm]
puts [gets $fh] ;# ==> P6
puts [gets $fh] ;# ==> 150 150
puts [gets $fh] ;# ==> 255
binary scan [read $fh 3] c3 pixel
foreach colour $pixel {puts [expr {$colour & 0xff}]} ;# ==> 255 \n 0 \n 0 \n
close $fh
[edit] Visual Basic .NET
Public Shared Sub SaveRasterBitmapToPpmFile(ByVal rasterBitmap As RasterBitmap, ByVal filepath As String)
Dim header As String = String.Format("P6{0}{1}{2}{3}{0}255{0}", vbLf, rasterBitmap.Width, " "c, rasterBitmap.Height)
Dim bufferSize As Integer = header.Length + (rasterBitmap.Width * rasterBitmap.Height * 3)
Dim bytes(bufferSize - 1) As Byte
Buffer.BlockCopy(Encoding.ASCII.GetBytes(header.ToString), 0, bytes, 0, header.Length)
Dim index As Integer = header.Length
For y As Integer = 0 To rasterBitmap.Height - 1
For x As Integer = 0 To rasterBitmap.Width - 1
Dim color As Rgb = rasterBitmap.GetPixel(x, y)
bytes(index) = color.R
bytes(index + 1) = color.G
bytes(index + 2) = color.B
index += 3
Next
Next
My.Computer.FileSystem.WriteAllBytes(filepath, bytes, False)
End Sub
[edit] Vedit macro language
This routine creates a RAW PPM file (binary). Pixel data must be stored in edit buffer pointed by numeric register #10. The data in the buffer is assumed to be in R,G,B order, which is the order used by PPM file.
/////////////////////////////////////////////////////////////////////
//
// Save image as PPM file.
// @10 = filename. Buffer #10 contains the Pixel data.
//
:SAVE_PPM:
Buf_Switch(#10)
BOF
IT("P6") IN
Num_Ins(#11, LEFT) // width of image
Num_Ins(#12, LEFT) // height of image
Num_Ins(255, LEFT+NOCR) // maxval
IC(10)
File_Save_As(@10, OK)
Return
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