Even mooier getyped die functies in xml_helper_functs

docs/report.tex

@@ -224,10 +224,9 @@ reader will only get results from this version.
 Now we are only interested in the individual characters so we can skip the
 location of the entire license plate. Each character has 
 a single character value, indicating what someone thought what the letter or
-digit was and four coordinates to create a bounding box. To make things not to
-complicated a Character class and Point class are used. They
-act pretty much as associative lists, but it gives extra freedom on using the
-data. If less then four points have been set the character will not be saved.
+digit was and four coordinates to create a bounding box. If less then four points have been set the character will not be saved. Else, to make things not to
+complicated, a Character class is used. It acts as an associative list, but it gives some extra freedom when using the
+data.
 
 When four points have been gathered the data from the actual image is being
 requested. For each corner a small margin is added (around 3 pixels) so that no

src/LicensePlate.py

 class LicensePlate:
-
     def __init__(self, country=None, characters=None):
         self.country = country
         self.characters = characters
\ No newline at end of file

src/Point.py

-class Point:
-    def __init__(self, x, y):
-        self.x = x
-        self.y = y
-
-    def to_tuple(self):
-        return self.x, self.y
-        
-    def __str__(self):
-        return str(self.x) + " " + str(self.y)
\ No newline at end of file

src/xml_helper_functions.py

 from os import mkdir
 from os.path import exists
-from math import acos
 from pylab import imsave, array, zeros, inv, dot, norm, svd, floor
 from xml.dom.minidom import parse
-from Point import Point
 from Character import Character
 from GrayscaleImage import GrayscaleImage
 from NormalizedCharacterImage import NormalizedCharacterImage
 from LicensePlate import LicensePlate
 
-# sets the entire license plate of an image
-def retrieve_data(image, corners):
-    x0, y0 = corners[0].to_tuple()
-    x1, y1 = corners[1].to_tuple()
-    x2, y2 = corners[2].to_tuple()
-    x3, y3 = corners[3].to_tuple()
+# Gets the character data from a picture with a license plate
+def retrieve_data(plate, corners):
+    x0,y0, x1,y1, x2,y2, x3,y3 = corners
 
-    M = int(1.2 * (max(x0, x1, x2, x3) - min(x0, x1, x2, x3)))
+    M = max(x0, x1, x2, x3) - min(x0, x1, x2, x3)
     N = max(y0, y1, y2, y3) - min(y0, y1, y2, y3)
 
     matrix = array([
@@ -30,7 +25,7 @@ def retrieve_data(image, corners):
       [ 0,  0, 0, x3, y3, 1, -N * x3, -N * y3, -N]
     ])
 
-    P = inv(get_transformation_matrix(matrix))
+    P = get_transformation_matrix(matrix)
     data = array([zeros(M, float)] * N)
 
     for i in range(M):
@@ -39,7 +34,7 @@ def retrieve_data(image, corners):
             or_coor_h = (or_coor[1][0] / or_coor[2][0],
                          or_coor[0][0] / or_coor[2][0])
 
-            data[j][i] = pV(image, or_coor_h[0], or_coor_h[1])
+            data[j][i] = pV(plate, or_coor_h[0], or_coor_h[1])
 
     return data
 
@@ -51,108 +46,92 @@ def get_transformation_matrix(matrix):
     U, D, V = svd(matrix)
     p = V[8][:]
 
-    return array([
-        [ p[0], p[1], p[2] ],
-        [ p[3], p[4], p[5] ],
-        [ p[6], p[7], p[8] ]
-    ])
+    return inv(array([[p[0],p[1],p[2]], [p[3],p[4],p[5]], [p[6],p[7],p[8]]]))
 
 def pV(image, x, y):
     #Get the value of a point (interpolated x, y) in the given image
-    if image.in_bounds(x, y):
-        x_low  = floor(x)
-        x_high = floor(x + 1)
-        y_low  = floor(y)
-        y_high = floor(y + 1)
-        x_y    = (x_high - x_low) * (y_high - y_low)
+    if not image.in_bounds(x, y):
+      return 0
 
-        a = x_high - x
-        b = y_high - y
-        c = x - x_low
-        d = y - y_low
+    x_low, x_high = floor(x), floor(x+1)
+    y_low, y_high = floor(y), floor(y+1)
+    x_y    = (x_high - x_low) * (y_high - y_low)
 
-        return image[x_low,  y_low] / x_y * a * b \
-            + image[x_high,  y_low] / x_y * c * b \
-            + image[x_low , y_high] / x_y * a * d \
-            + image[x_high, y_high] / x_y * c * d
+    a = x_high - x
+    b = y_high - y
+    c = x - x_low
+    d = y - y_low
 
-    return 0
+    return image[x_low,  y_low] / x_y * a * b \
+        + image[x_high,  y_low] / x_y * c * b \
+        + image[x_low , y_high] / x_y * a * d \
+        + image[x_high, y_high] / x_y * c * d
 
 def xml_to_LicensePlate(filename, save_character=None):
-    image = GrayscaleImage('../images/Images/%s.jpg' % filename)
-    dom   = parse('../images/Infos/%s.info' % filename)
-    result_characters = []
-
-    version = dom.getElementsByTagName("current-version")[0].firstChild.data
-    info    = dom.getElementsByTagName("info")
-
-    for i in info:
-        if version == i.getElementsByTagName("version")[0].firstChild.data:
+    plate   = GrayscaleImage('../images/Images/%s.jpg' % filename)
+    dom     = parse('../images/Infos/%s.info' % filename)
+    country = ''
+    result  = []
+    version = get_node(dom, "current-version")
+    infos   = by_tag(dom, "info")
 
-            country = i.getElementsByTagName("identification-letters")[0].firstChild.data
-            temp = i.getElementsByTagName("characters")
+    for info in infos:
+        if not version == get_node(info, "version"):
+            continue
 
-            if len(temp):
-              characters = temp[0].childNodes
-            else:
-              characters = []
-              break
+        country = get_node(info, "identification-letters")
+        temp    = by_tag(info, "characters")
 
-            for i, character in enumerate(characters):
-                if character.nodeName == "character":
-                    value   = character.getElementsByTagName("char")[0].firstChild.data
-                    corners = get_corners(character)
+        if not temp: # no characters where found in the file
+            break
 
-                    if not len(corners) == 4:
-                      break
+        characters = temp[0].childNodes
 
-                    character_data  = retrieve_data(image, corners)
-                    character_image = NormalizedCharacterImage(data=character_data)
+        for i, char in enumerate(characters):
+            if not char.nodeName == "character":
+              continue
 
-                    result_characters.append(Character(value, corners, character_image, filename))
-                
-                    if save_character:
-                        single_character = GrayscaleImage(data=character_data)
+            value   = get_node(char, "char")
+            corners = get_corners(char)
 
-                        path = "../images/LearningSet/%s" % value
-                        image_path = "%s/%d_%s.jpg" % (path, i, filename.split('/')[-1])
+            if not len(corners) == 8:
+                break
 
-                        if not exists(path):
-                          mkdir(path)
+            data  = retrieve_data(plate, corners)
+            image = NormalizedCharacterImage(data=data)
+            result.append(Character(value, corners, image, filename))
+        
+            if save_character:
+                character_image = GrayscaleImage(data=data)
+                path       = "../images/LearningSet/%s" % value
+                image_path = "%s/%d_%s.jpg" % (path, i, filename.split('/')[-1])
 
-                        if not exists(image_path):
-                          single_character.save(image_path)
+                if not exists(path):
+                  mkdir(path)
 
-    return LicensePlate(country, result_characters)
+                if not exists(image_path):
+                  character_image.save(image_path)
 
-def get_corners(dom):
-  nodes = dom.getElementsByTagName("point")
-  corners = []
-
-  margin_y = 3
-  margin_x = 2
+    return LicensePlate(country, result)
 
-  corners.append(
-    Point(get_coord(nodes[0], "x") - margin_x, 
-          get_coord(nodes[0], "y") - margin_y)
-  )
+def get_node(node, tag):
+    return by_tag(node, tag)[0].firstChild.data
 
-  corners.append(
-    Point(get_coord(nodes[1], "x") + margin_x, 
-          get_coord(nodes[1], "y") - margin_y)
-  )
+def by_tag(node, tag):
+    return node.getElementsByTagName(tag)
 
-  corners.append(
-    Point(get_coord(nodes[2], "x") + margin_x, 
-          get_coord(nodes[2], "y") + margin_y)
-  )
+def get_attr(node, attr):
+  return int(node.getAttribute(attr))
 
-  corners.append(
-    Point(get_coord(nodes[3], "x") - margin_x, 
-          get_coord(nodes[3], "y") + margin_y)
-  )
+def get_corners(dom):
+    p = by_tag(dom, "point")
 
-  return corners
+    # Extra padding
+    y = 3
+    x = 2
 
-def get_coord(node, attribute):
-  return int(node.getAttribute(attribute))
\ No newline at end of file
+    # return 8 values (x0,y0, .., x3,y3)
+    return get_attr(p[0], "x") - x, get_attr(p[0], "y") - y,\
+           get_attr(p[1], "x") + x, get_attr(p[1], "y") - y,\
+           get_attr(p[2], "x") + x, get_attr(p[2], "y") + y,\
+           get_attr(p[3], "x") - x, get_attr(p[3], "y") + y