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Task/Bitmap-PPM-conversion-through-a-pipe/0DESCRIPTION

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+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 <tt>output_ppm</tt> 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).

Task/Bitmap-PPM-conversion-through-a-pipe/1META.yaml

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+---
+note: Raster graphics operations

Task/Bitmap-PPM-conversion-through-a-pipe/C/bitmap-ppm-conversion-through-a-pipe-1.c

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+/* interface */
+void print_jpg(image img, int qual);

Task/Bitmap-PPM-conversion-through-a-pipe/C/bitmap-ppm-conversion-through-a-pipe-2.c

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+#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);
+   }
+}

Task/Bitmap-PPM-conversion-through-a-pipe/C/bitmap-ppm-conversion-through-a-pipe-3.c

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+#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);
+}

Task/Bitmap-PPM-conversion-through-a-pipe/Go/bitmap-ppm-conversion-through-a-pipe-1.go

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+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)
+    }
+}

Task/Bitmap-PPM-conversion-through-a-pipe/Go/bitmap-ppm-conversion-through-a-pipe-2.go

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+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 -> ()
+;;

Task/Bitmap-PPM-conversion-through-a-pipe/PicoLisp/bitmap-ppm-conversion-through-a-pipe.l

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+# 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"))

Task/Bitmap-PPM-conversion-through-a-pipe/Ruby/bitmap-ppm-conversion-through-a-pipe.rb

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+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')

Task/Bitmap-PPM-conversion-through-a-pipe/Tcl/bitmap-ppm-conversion-through-a-pipe-1.tcl

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+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
+}

Task/Bitmap-PPM-conversion-through-a-pipe/Tcl/bitmap-ppm-conversion-through-a-pipe-2.tcl

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+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