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{{task|Raster graphics operations}}
Using the data storage type defined [[Basic_bitmap_storage|on this page]] for raster images, delegate writing a JPEG file through a '''pipe''' using the output_ppm function defined [[Write_ppm_file|on this other page]].
There are various utilities that can be used for this task, for example: '''cjpeg''' (package ''"jpeg-progs"'' on Linux), '''ppmtojpeg''' (package ''"netpbm"'' on Linux), '''convert''' (from ''ImageMagick'', multi-platform).
C
{{works with|POSIX|.1-2001}} This one uses the ImageMagick convert tool.
/* interface */ void print_jpg(image img, int qual);
#define MAXCMDBUF 100 void print_jpg(image img, int qual) { char buf[MAXCMDBUF]; unsigned int n; FILE *pipe; snprintf(buf, MAXCMDBUF, "convert ppm:- -quality %d jpg:-", qual); pipe = popen(buf, "w"); if ( pipe != NULL ) { fprintf(pipe, "P6\n%d %d\n255\n", img->width, img->height); n = img->width * img->height; fwrite(img->buf, sizeof(pixel), n, pipe); pclose(pipe); } }
The code that writes to the pipe is the same of [[Write_ppm_file|output_ppm]] of course. A complete example is
#include "imglib.h" int main() { image img; img = alloc_img(100,100); fill_img(img, 50, 20, 200); draw_line(img, 0, 0, 80, 80, 255, 0, 0); print_jpg(img, 75); free_img(img); }
In order to make it working, you must link it with the raster image functions given by the codes [[Bresenham's_line_algorithm#C|here]] and [[Basic_bitmap_storage#C|here]]
Go
{{works with|Go weekly.2011-12-14}} (Go 1 should be close) Using cjpeg:
package main // Files required to build supporting package raster are found in: // * Bitmap // * Write a PPM file import ( "fmt" "math/rand" "os/exec" "raster" ) func main() { b := raster.NewBitmap(400, 300) // a little extravagant, this draws a design of dots and lines b.FillRgb(0xc08040) for i := 0; i < 2000; i++ { b.SetPxRgb(rand.Intn(400), rand.Intn(300), 0x804020) } for x := 0; x < 400; x++ { for y := 240; y < 245; y++ { b.SetPxRgb(x, y, 0x804020) } for y := 260; y < 265; y++ { b.SetPxRgb(x, y, 0x804020) } } for y := 0; y < 300; y++ { for x := 80; x < 85; x++ { b.SetPxRgb(x, y, 0x804020) } for x := 95; x < 100; x++ { b.SetPxRgb(x, y, 0x804020) } } // pipe logic c := exec.Command("cjpeg", "-outfile", "pipeout.jpg") pipe, err := c.StdinPipe() if err != nil { fmt.Println(err) return } err = c.Start() if err != nil { fmt.Println(err) return } err = b.WritePpmTo(pipe) if err != nil { fmt.Println(err) return } err = pipe.Close() if err != nil { fmt.Println(err) } }
Julia
{{works with|Julia|0.6}}
using Images, FileIO ppmimg = load("data/bitmapInputTest.ppm") save("data/bitmapOutputTest.jpg", ppmimg)
Kotlin
{{works with|Ubuntu 16.04}} In order to provide a complete runnable example, we repeat bits of code from other relevant tasks and add code which pipes .ppm data to ImageMagick's 'convert' tool which then writes the corresponding .jpg file to disk.
// Version 1.2.40 import java.awt.Color import java.awt.Graphics import java.awt.image.BufferedImage 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 the object in PPM format to ImageMagick's STDIN via a pipe // so it can be converted to a .jpg file and written to disk val pb = ProcessBuilder("convert", "-", "output_piped.jpg") pb.directory(null) pb.redirectInput(ProcessBuilder.Redirect.PIPE) val buffer = ByteArray(width * 3) // write one line at a time val proc = pb.start() val pStdIn = proc.outputStream pStdIn.use { val header = "P6\n$width $height\n255\n".toByteArray() with (it) { write(header) for (y in 0 until height) { for (x in 0 until width) { val c = bbs.getPixel(x, y) buffer[x * 3] = c.red.toByte() buffer[x * 3 + 1] = c.green.toByte() buffer[x * 3 + 2] = c.blue.toByte() } write(buffer) } } } }
Mathematica
The Windows command line does not like quotes in the middle of text, so strings have been turned into character codes.
convert[image_,out_]:=Module[{process=StartProcess[{
"wolfram","-noinit","-noprompt","-run",
"Export[FromCharacterCode["~~ToString[ToCharacterCode[out]]~~"],ImportString[StringRiffle[Table[InputString[],{4}],FromCharacterCode[10]],FromCharacterCode[{80,80,77}]]]"
}]},
WriteLine[process,image];
WriteLine[process,"Quit[]"];
];
== {{Header|OCaml}} ==
let print_jpeg ~img ?(quality=96) () = let cmd = Printf.sprintf "cjpeg -quality %d" quality in (* let cmd = Printf.sprintf "ppmtojpeg -quality %d" quality in let cmd = Printf.sprintf "convert ppm:- -quality %d jpg:-" quality in *) let ic, oc = Unix.open_process cmd in output_ppm ~img ~oc; try while true do let c = input_char ic in print_char c done with End_of_file -> () ;;
Perl 6
#!/usr/bin/env perl6
# Reference:
# https://rosettacode.org/wiki/Bitmap/Write_a_PPM_file#Perl_6
use v6;
class Pixel { has uint8 ($.R, $.G, $.B) }
class Bitmap {
has UInt ($.width, $.height);
has Pixel @!data;
method fill(Pixel $p) {
@!data = $p.clone xx ($!width*$!height)
}
method pixel(
$i where ^$!width,
$j where ^$!height
--> Pixel
) is rw { @!data[$i*$!height + $j] }
method data { @!data }
}
role PPM {
method P6 returns Blob {
"P6\n{self.width} {self.height}\n255\n".encode('ascii')
~ Blob.new: flat map { .R, .G, .B }, self.data
}
}
my Bitmap $b = Bitmap.new(width => 125, height => 125) but PPM;
for flat ^$b.height X ^$b.width -> $i, $j {
$b.pixel($i, $j) = Pixel.new: :R($i*2), :G($j*2), :B(255-$i*2);
}
my $proc = run '/usr/bin/convert','-','output_piped.jpg', :in;
$proc.in.write: $b.P6;
$proc.in.close;
{{out}}
file output_piped.jpg
output_piped.jpg: JPEG image data, JFIF standard 1.01, aspect ratio, density 1x1, segment length 16, baseline, precision 8, 125x125, frames 3
PicoLisp
# Create an empty image of 120 x 90 pixels
(setq *Ppm (make (do 90 (link (need 120)))))
# Fill background with green color
(ppmFill *Ppm 0 255 0)
# Draw a diagonal line
(for I 80 (ppmSetPixel *Ppm I I 0 0 0))
# Write to "img.jpg" through a pipe
(ppmWrite *Ppm '("convert" "-" "img.jpg"))
Python
""" Adapted from https://stackoverflow.com/questions/26937143/ppm-to-jpeg-jpg-conversion-for-python-3-4-1 Requires pillow-5.3.0 with Python 3.7.1 32-bit on Windows. Sample ppm graphics files from http://www.cs.cornell.edu/courses/cs664/2003fa/images/ """ from PIL import Image im = Image.open("boxes_1.ppm") im.save("boxes_1.jpg")
Does not need to pipe through a conversion utility because the Pillow module does the conversion.
Racket
(define (ppm->jpeg bitmap [jpg-file "output"] [quality 75])
(define command (format "convert ppm:- -quality ~a jpg:~a.jpg" quality jpg-file))
(match-define (list in out pid err ctrl) (process command))
(bitmap->ppm bitmap out)
(close-input-port in)
(close-output-port out))
(ppm->jpeg bm)
Ruby
Extends [[Write ppm file#Ruby]]. Uses the ImageMagick convert
tool.
Additionally, for debugging, allow writing in pixmap P3 (ascii) format.
class Pixmap PIXMAP_FORMATS = ["P3", "P6"] # implemented output formats PIXMAP_BINARY_FORMATS = ["P6"] # implemented output formats which are binary def write_ppm(ios, format="P6") if not PIXMAP_FORMATS.include?(format) raise NotImplementedError, "pixmap format #{format} has not been implemented" end ios.puts format, "#{@width} #{@height}", "255" ios.binmode if PIXMAP_BINARY_FORMATS.include?(format) @height.times do |y| @width.times do |x| case format when "P3" then ios.print @data[x][y].values.join(" "),"\n" when "P6" then ios.print @data[x][y].values.pack('C3') end end end end def save(filename, opts={:format=>"P6"}) File.open(filename, 'w') do |f| write_ppm(f, opts[:format]) end end def print(opts={:format=>"P6"}) write_ppm($stdout, opts[:format]) end def save_as_jpeg(filename, quality=75) pipe = IO.popen("convert ppm:- -quality #{quality} jpg:#{filename}", 'w') write_ppm(pipe) pipe.close end end image = Pixmap.open('file.ppm') image.save_as_jpeg('file.jpg')
Tcl
Referring to [[Write ppm file#Tcl]] and [[Basic bitmap storage#Tcl]]
{{libheader|Tk}}
package require Tk proc output_jpeg {image filename {quality 75}} { set f [open |[list convert ppm:- -quality $quality jpg:- > $filename] w] fconfigure $f -translation binary puts -nonewline $f [$image data -format ppm] close $f }
However, it is more normal to do this directly with the {{libheader|TkImg}} which is bundled with many Tcl distributions.
package require Tk package require img::jpeg proc output_jpeg {image filename} { $image write $filename -format jpeg } set img [image create photo -filename filename.ppm] output_jpeg $img filename.jpg
zkl
{{trans|C}} Uses the PPM class from http://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm#zkl
Using the convert utility by ImageMagick:
img:=PPM.readPPMFile("fractal.ppm");
p:=System.popen(0'|convert ppm:- jpg:"fractal.jpg"|,"w");
img.write(p); p.close();
{{omit from|GUISS}} {{omit from|PARI/GP}} {{omit from|TI-83 BASIC}} {{omit from|TI-89 BASIC}} {{omit from|ZX Spectrum Basic|Does not have pipelining}}