CDE

Task/Bitmap-Read-a-PPM-file/Common-Lisp/bitmap-read-a-ppm-file-1.lisp

@@ -0,0 +1,71 @@
+(in-package #:rgb-pixel-buffer)
+
+(defparameter *whitespaces-chars* '(#\SPACE #\RETURN #\TAB #\NEWLINE #\LINEFEED))
+
+(defun read-header-chars (stream &optional (delimiter-list *whitespaces-chars*))
+  (do ((c (read-char stream nil :eof)
+          (read-char stream nil :eof))
+       (vals nil (if (or (null c) (char= c  #\#)) vals (cons c vals))))   ;;don't collect comment chars
+       ((or (eql c :eof) (member c delimiter-list)) (map 'string #'identity (nreverse vals)))   ;;return strings
+    (when (char= c #\#)   ;;skip comments
+      (read-line stream))))
+
+(defun read-ppm-file-header (file)
+  (with-open-file (s file :direction :input)
+    (do ((failure-count 0 (1+ failure-count))
+	 (tokens nil (let ((t1 (read-header-chars s)))
+		       (if (> (length t1) 0)
+			   (cons t1 tokens)
+			   tokens))))
+	((>= (length tokens) 4) (values (nreverse tokens)
+			      (file-position s)))
+      (when (>= failure-count 10)
+	(error (format nil "File ~a does not seem to be a proper ppm file - maybe too many comment lines" file)))
+      (when (= (length tokens) 1)
+	(when (not (or (string= (first tokens) "P6") (string= (first tokens) "P3")))
+	  (error (format nil "File ~a is not a ppm file - wrong magic-number. Read ~a instead of P6 or P3 " file (first tokens))))))))
+
+(defun read-ppm-image (file)
+  (flet ((image-data-reader (stream start-position width height image-build-function read-function)
+	   (file-position stream start-position)
+	   (dotimes (row height)
+	     (dotimes (col width)
+	       (funcall image-build-function row col (funcall read-function stream))))))
+    (multiple-value-bind (header file-pos) (read-ppm-file-header file)
+      (let* ((image-type (first header))
+	     (width (parse-integer (second header) :junk-allowed t))
+	     (height (parse-integer (third header) :junk-allowed t))
+	     (max-value (parse-integer (fourth header) :junk-allowed t))
+	     (image (make-rgb-pixel-buffer width height)))
+	(when (> max-value 255)
+	  (error "unsupported depth - convert to 1byte depth with pamdepth"))
+	(cond ((string= "P6" image-type)
+	       (with-open-file (stream file :direction :input :element-type '(unsigned-byte 8))
+		 (image-data-reader stream
+				    file-pos
+				    width
+				    height
+				    #'(lambda (w h val)
+					(setf (rgb-pixel image w h) val))
+				    #'(lambda (stream)
+					(make-rgb-pixel (read-byte stream)
+							(read-byte stream)
+							(read-byte stream))))
+		 image))
+	      ((string= "P3" image-type)
+	       (with-open-file (stream file :direction :input)
+		 (image-data-reader stream
+				    file-pos
+				    width
+				    height
+				    #'(lambda (w h val)
+					(setf (rgb-pixel image w h) val))
+				    #'(lambda (stream)
+					(make-rgb-pixel (read stream)
+							(read stream)
+							(read stream))))
+		 image))
+	      (t 'unsupported))
+      image))))
+
+(export 'read-ppm-image)

Task/Bitmap-Read-a-PPM-file/Common-Lisp/bitmap-read-a-ppm-file-2.lisp

@@ -0,0 +1 @@
+(read-ppm-image "feep.ppm")

Task/Bitmap-Read-a-PPM-file/E/bitmap-read-a-ppm-file-1.e

@@ -0,0 +1,55 @@
+def chr := <import:java.lang.makeCharacter>.asChar
+
+def readPPM(inputStream) {
+  # Proper native-to-E stream IO facilities have not been designed and
+  # implemented yet, so we are borrowing Java's. Poorly. This *will* be
+  # improved eventually.
+
+  # Reads one header token, skipping comments and whitespace, and exactly
+  # one trailing whitespace character
+  def readToken() {
+    var token := ""
+    var c := chr(inputStream.read())
+    while (c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '#') {
+      if (c == '#') {
+        while (c != '\n') { c := chr(inputStream.read()) }
+      }
+      # skip over initial whitespace
+      c := chr(inputStream.read())
+    }
+    while (!(c == ' ' || c == '\t' || c == '\r' || c == '\n')) {
+      if (c == '#') {
+        while (c != '\n') { c := chr(inputStream.read()) }
+      } else {
+        token += E.toString(c)
+        c := chr(inputStream.read())
+      }
+    }
+    return token
+  }
+
+  # Header
+  require(readToken() == "P6")
+  def width := __makeInt(readToken())
+  def height := __makeInt(readToken())
+  def maxval := __makeInt(readToken())
+
+  def size := width * height * 3
+
+  # Body
+  # See [[Basic bitmap storage]] for the definition and origin of sign()
+  def data := <elib:tables.makeFlexList>.fromType(<type:java.lang.Byte>, size)
+  if (maxval >= 256) {
+    for _ in 1..size {
+      data.push(sign((inputStream.read() * 256 + inputStream.read()) * 255 // maxval))
+    }
+  } else {
+    for _ in 1..size {
+      data.push(sign(inputStream.read() * 255 // maxval))
+    }
+  }
+
+  def image := makeImage(width, height)
+  image.replace(data.snapshot())
+  return image
+}

Task/Bitmap-Read-a-PPM-file/E/bitmap-read-a-ppm-file-2.e

@@ -0,0 +1,6 @@
+def readPPMTask(inputFile, outputFile) {
+  makeGrayscale \
+    .fromColor(readPPM(<import:java.io.makeFileInputStream>(inputFile))) \
+    .toColor() \
+    .writePPM(<import:java.io.makeFileOutputStream>(outputFile))
+}

Task/Bitmap-Read-a-PPM-file/Euphoria/bitmap-read-a-ppm-file-1.euphoria

@@ -0,0 +1,41 @@
+include get.e
+
+function get2(integer fn)
+    sequence temp
+    temp = get(fn)
+    return temp[2] - temp[1]*temp[1]
+end function
+
+function read_ppm(sequence filename)
+    sequence image, line
+    integer dimx, dimy, maxcolor
+    atom fn
+    fn = open(filename, "rb")
+    if fn < 0 then
+        return -1 -- unable to open
+    end if
+    line = gets(fn)
+    if not equal(line,"P6\n") then
+        return -1 -- only ppm6 files are supported
+    end if
+    dimx = get2(fn)
+    if dimx < 0 then
+        return -1
+    end if
+    dimy = get2(fn)
+    if dimy < 0 then
+        return -1
+    end if
+    maxcolor = get2(fn)
+    if maxcolor != 255 then
+        return -1 -- maxcolors other then 255 are not supported
+    end if
+    image = repeat(repeat(0,dimy),dimx)
+    for y = 1 to dimy do
+        for x = 1 to dimx do
+            image[x][y] = getc(fn)*#10000 + getc(fn)*#100 + getc(fn)
+        end for
+    end for
+    close(fn)
+    return image
+end function

Task/Bitmap-Read-a-PPM-file/Euphoria/bitmap-read-a-ppm-file-2.euphoria

@@ -0,0 +1,5 @@
+sequence image
+image = read_ppm("image.ppm")
+image = to_gray(image)
+image = to_color(image)
+write_ppm("image_gray.ppm",image)