Use connected-component labeling for finding letters.

pixelocr/gui/pageview.py

@@ -60,12 +60,13 @@ class PageScene(QGraphicsScene):
         self.pageItem.setGraphicsEffect(shadow)
 
         letterPen = QPen(QColor(50, 50, 50, 100))
-        letterBrush = QBrush(QColor(255, 255, 0, 60))
+        letterBrush = QBrush(QColor(255, 255, 0, 80))
         linePen = QPen(QColor(255, 150, 150, 100))
         for line in page:
-            for letter in line:
-                if not letter.image.isspace:
-                    self.addRect(letter.x1, letter.y1, letter.width, letter.height, letterPen, letterBrush)
+            for word in line:
+                for letter in word:
+                    if not letter.image.isspace:
+                        self.addRect(letter.x1, letter.y1, letter.width, letter.height, letterPen, letterBrush)
             self.addRect(line.x1, line.y1, line.width, line.height, Qt.red)
 
     def addPage(self, page):

pixelocr/image.py

@@ -151,22 +151,36 @@ class Image(object):
         bottom_margin = _get_margin_height(reversed(self.bitmap))
         return self[top_margin:self.height - bottom_margin, :]
 
-    def _iter_lines(self, min_space, T=False):
-        line_start = None
-        prev_line_end = 0
+    def _iter_lines(self, min_space):
+        def iter_lines():
+            line_start = None
+            prev_line_end = 0
 
-        for i, row in enumerate(self.bitmap):
-            if _is_nonblank(row):
-                if line_start is None:
-                    line_start = i
-                    height = line_start - prev_line_end
-                    if height >= min_space:
-                        yield self[prev_line_end:line_start]
-            else:
-                if line_start is not None:
-                    yield self[line_start:i,:]
-                    line_start = None  
-                    prev_line_end = i
+            for i, row in enumerate(self.bitmap):
+                if _is_nonblank(row):
+                    if line_start is None:
+                        line_start = i
+                else:
+                    if line_start is not None:
+                        yield self[line_start:i,:]
+                        line_start = None  
+                        prev_line_end = i
+
+        def merge_lines(lines):
+            prev_line = None
+            for line in lines:
+                if prev_line is None:
+                    prev_line = line
+                else:
+                    if line.y1 - prev_line.y2 < min_space: 
+                        prev_line = self[prev_line.y1:line.y2]
+                    else:
+                        yield prev_line
+                        prev_line = line
+            if prev_line is not None:
+                yield prev_line
+
+        return merge_lines(iter_lines())
 
 
 class SubImage(Image):

pixelocr/page.py

@@ -14,9 +14,14 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+from scipy import ndimage
+
 from .image import Image
 
 
+CONNECTIVITY8 = ndimage.generate_binary_structure(2, 2)
+
+
 class PageObject(object):
     def __init__(self, image):
         self.image = image
@@ -55,14 +60,24 @@ class PageObject(object):
 
 class Page(PageObject):
     def __iter__(self):
-        for line_img in self.image._iter_lines(min_space=200):
+        for line_img in self.image._iter_lines(min_space=5):
             yield Line(line_img)
 
 
 class Line(PageObject):
     def __iter__(self):
-        for rotated_letter_img in self.image.T._iter_lines(min_space=10, T=True):
-            yield Letter(rotated_letter_img.T.strip())
+        for rotated_word_img in self.image.T._iter_lines(min_space=10):
+            yield Word(rotated_word_img.T)
+
+
+class Word(PageObject):
+    def __iter__(self):
+        labels, max_label = ndimage.label(self.image.bitmap, CONNECTIVITY8)
+        obj_indices = ndimage.find_objects(labels, max_label)
+        letter_images = (self.image[obj_index] for obj_index in obj_indices)
+        letters = (Letter(image) for image in letter_images)
+        sorted_letters = sorted(letters, key=lambda letter: (letter.x1, -letter.y1))
+        return iter(sorted_letters)
 
 
 class Letter(PageObject):