Storing Bezier path and dashing style of line in LTCurve (#801)

* Fixes #672 and #630

Add raw points to get full information from bezier segments and dashing style

* Use intermediate variables for constructing tranformed_path

Co-authored-by: Pieter Marsman <pietermarsman@gmail.com>

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Output converter for the hOCR format ([#651](https://github.com/pdfminer/pdfminer.six/pull/651))
 - Font name aliases for Arial, Courier New and Times New Roman ([#790](https://github.com/pdfminer/pdfminer.six/pull/790))
 - Documentation on why special characters can sometimes not be extracted ([#829](https://github.com/pdfminer/pdfminer.six/pull/829))
+- Storing Bezier path and dashing style of line in LTCurve ([#801](https://github.com/pdfminer/pdfminer.six/pull/801))
 
 ### Fixed
 

pdfminer/converter.py

@@ -138,6 +138,19 @@ class PDFLayoutAnalyzer(PDFTextDevice):
             ]
             pts = [apply_matrix_pt(self.ctm, pt) for pt in raw_pts]
 
+            operators = [str(operation[0]) for operation in path]
+            transformed_points = [
+                [
+                    apply_matrix_pt(self.ctm, (float(operand1), float(operand2)))
+                    for operand1, operand2 in zip(operation[1::2], operation[2::2])
+                ]
+                for operation in path
+            ]
+            transformed_path = [
+                cast(PathSegment, (o, *p))
+                for o, p in zip(operators, transformed_points)
+            ]
+
             if shape in {"mlh", "ml"}:
                 # single line segment
                 #
@@ -152,6 +165,8 @@ class PDFLayoutAnalyzer(PDFTextDevice):
                     evenodd,
                     gstate.scolor,
                     gstate.ncolor,
+                    original_path=transformed_path,
+                    dashing_style=gstate.dash,
                 )
                 self.cur_item.add(line)
 
@@ -171,6 +186,8 @@ class PDFLayoutAnalyzer(PDFTextDevice):
                         evenodd,
                         gstate.scolor,
                         gstate.ncolor,
+                        transformed_path,
+                        gstate.dash,
                     )
                     self.cur_item.add(rect)
                 else:
@@ -182,9 +199,10 @@ class PDFLayoutAnalyzer(PDFTextDevice):
                         evenodd,
                         gstate.scolor,
                         gstate.ncolor,
+                        transformed_path,
+                        gstate.dash,
                     )
                     self.cur_item.add(curve)
-
             else:
                 curve = LTCurve(
                     gstate.linewidth,
@@ -194,6 +212,8 @@ class PDFLayoutAnalyzer(PDFTextDevice):
                     evenodd,
                     gstate.scolor,
                     gstate.ncolor,
+                    transformed_path,
+                    gstate.dash,
                 )
                 self.cur_item.add(curve)
 

pdfminer/layout.py

@@ -20,7 +20,7 @@ from .pdffont import PDFFont
 from .pdfinterp import Color
 from .pdfinterp import PDFGraphicState
 from .pdftypes import PDFStream
-from .utils import INF
+from .utils import INF, PathSegment
 from .utils import LTComponentT
 from .utils import Matrix
 from .utils import Plane
@@ -210,7 +210,14 @@ class LTComponent(LTItem):
 
 
 class LTCurve(LTComponent):
-    """A generic Bezier curve"""
+    """
+    A generic Bezier curve
+
+    The parameter `original_path` contains the original
+    pathing information from the pdf (e.g. for reconstructing Bezier Curves).
+
+    `dashing_style` contains the Dashing information if any.
+    """
 
     def __init__(
         self,
@@ -221,6 +228,8 @@ class LTCurve(LTComponent):
         evenodd: bool = False,
         stroking_color: Optional[Color] = None,
         non_stroking_color: Optional[Color] = None,
+        original_path: Optional[List[PathSegment]] = None,
+        dashing_style: Optional[Tuple[object, object]] = None,
     ) -> None:
         LTComponent.__init__(self, get_bound(pts))
         self.pts = pts
@@ -230,6 +239,8 @@ class LTCurve(LTComponent):
         self.evenodd = evenodd
         self.stroking_color = stroking_color
         self.non_stroking_color = non_stroking_color
+        self.original_path = original_path
+        self.dashing_style = dashing_style
 
     def get_pts(self) -> str:
         return ",".join("%.3f,%.3f" % p for p in self.pts)
@@ -251,6 +262,8 @@ class LTLine(LTCurve):
         evenodd: bool = False,
         stroking_color: Optional[Color] = None,
         non_stroking_color: Optional[Color] = None,
+        original_path: Optional[List[PathSegment]] = None,
+        dashing_style: Optional[Tuple[object, object]] = None,
     ) -> None:
         LTCurve.__init__(
             self,
@@ -261,6 +274,8 @@ class LTLine(LTCurve):
             evenodd,
             stroking_color,
             non_stroking_color,
+            original_path,
+            dashing_style,
         )
 
 
@@ -279,6 +294,8 @@ class LTRect(LTCurve):
         evenodd: bool = False,
         stroking_color: Optional[Color] = None,
         non_stroking_color: Optional[Color] = None,
+        original_path: Optional[List[PathSegment]] = None,
+        dashing_style: Optional[Tuple[object, object]] = None,
     ) -> None:
         (x0, y0, x1, y1) = bbox
         LTCurve.__init__(
@@ -290,6 +307,8 @@ class LTRect(LTCurve):
             evenodd,
             stroking_color,
             non_stroking_color,
+            original_path,
+            dashing_style,
         )
 
 

tests/test_converter.py

@@ -216,6 +216,45 @@ class TestPaintPath:
             (71.41, 434.89),
         ]
 
+    def test_paint_path_beziers_check_raw(self):
+        """See section 4.4, table 4.9 of the PDF reference manual"""
+
+        def parse(path):
+            analyzer = self._get_analyzer()
+            analyzer.cur_item = LTContainer([0, 1000, 0, 1000])
+            analyzer.paint_path(PDFGraphicState(), False, False, False, path)
+            return analyzer.cur_item._objs
+
+        # "c" operator
+        assert parse(
+            [
+                ("m", 72.41, 433.89),
+                ("c", 72.41, 434.45, 71.96, 434.89, 71.41, 434.89),
+            ]
+        )[0].original_path == [
+            ("m", (72.41, 433.89)),
+            ("c", (72.41, 434.45), (71.96, 434.89), (71.41, 434.89)),
+        ]
+
+    def test_paint_path_dashed(self):
+        """See section 4.4, table 4.9 of the PDF reference manual"""
+
+        def parse(path):
+            analyzer = self._get_analyzer()
+            analyzer.cur_item = LTContainer([0, 1000, 0, 1000])
+            graphicstate = PDFGraphicState()
+            graphicstate.dash = ([1, 1], 0)
+            analyzer.paint_path(graphicstate, False, False, False, path)
+            return analyzer.cur_item._objs
+
+        # "c" operator
+        assert parse(
+            [
+                ("m", 72.41, 433.89),
+                ("c", 72.41, 434.45, 71.96, 434.89, 71.41, 434.89),
+            ]
+        )[0].dashing_style == ([1, 1], 0)
+
     def test_paint_path_without_starting_m(self):
         gs = PDFGraphicState()
         analyzer = self._get_analyzer()