Bitmap/Write a PPM file: Difference between revisions
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<lang perl>$img->image_set_format("jpeg"); # or png, tiff, ppm ...</lang> |
<lang perl>$img->image_set_format("jpeg"); # or png, tiff, ppm ...</lang> |
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=={{header|Tcl}}== |
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Referring to [[Basic bitmap storage#Tcl]]: |
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<lang tcl>package require Tk |
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set img [newImage 150 150] |
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fill $img red |
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setPixel $img green 40 40 |
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$img write filename.ppm -format ppm |
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# check the file format: |
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set fh [open filename.ppm] |
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puts [gets $fh] ;# ==> P6 |
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puts [gets $fh] ;# ==> 150 150 |
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puts [gets $fh] ;# ==> 255 |
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binary scan [read $fh 3] c3 pixel |
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foreach colour $pixel {puts [expr {$colour & 0xff}]} ;# ==> 255 \n 0 \n 0 \n |
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close $fh</lang> |
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=={{header|Vedit macro language}}== |
=={{header|Vedit macro language}}== |
Revision as of 20:56, 13 April 2009
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.)
Ada
<lang 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; </lang> 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.
C
Interface:
<lang c>void output_ppm(FILE *fd, image img);</lang>
Implementation:
<lang c>#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);
}</lang>
D
This describes modifications that needs to be done to class P6Image described on Read ppm file problem page.
Two additional imports are needed: <lang D> import tango.io.protocol.Writer; import tango.io.protocol.model.IWriter; </lang>
P6Image will implement IWritable interface <lang D> 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 }
} </lang>
Saving a file is easy as a pie: <lang D> auto p6 = new P6Image(new FileConduit("image.ppm")); auto write = new Writer(new FileConduit("out.ppm", FileConduit.WriteCreate));
write (p6); </lang>
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
It loads RCImageBasic
module, which is defined here.
<lang fortran>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</lang>
Haskell
<lang 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
h <- openFile path ReadMode let die = hClose h >> fail "readImage: bad format" ppm <- hGetContents h 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 hClose h 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 = do
h <- openFile path WriteMode (width, height) <- stToIO $ dimensions i let w = hPutStrLn h w $ magicNumber w $ show width ++ " " ++ show height if null maxval then return () else w maxval stToIO (getPixels i) >>= hPutStr h . toNetpbm hClose h where magicNumber = netpbmMagicNumber (nil :: c) maxval = netpbmMaxval (nil :: c)</lang>
Modula-3
Bitmap
is the module from Basic Bitmap Storage.
<lang modula3>INTERFACE PPM;
IMPORT Bitmap, Pathname;
PROCEDURE Create(imgfile: Pathname.T; img: Bitmap.T);
END PPM.</lang> <lang modula3>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.</lang>
OCaml
<lang 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;
- </lang>
Perl
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.)
<lang perl>#! /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"); $img->save("out0.png");
exit 0;</lang>
Normally Image::Imlib2 understands which output format to use from the extension; to override its guess, you can use:
<lang perl>$img->image_set_format("jpeg"); # or png, tiff, ppm ...</lang>
Tcl
Referring to Basic bitmap storage#Tcl: <lang tcl>package require Tk
set img [newImage 150 150] fill $img red setPixel $img green 40 40
$img write filename.ppm -format 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</lang>
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