Merge pull request #224 from socialcopsdev/fix-207

[MRG] Add plot types and update docs

HISTORY.md

@@ -4,6 +4,18 @@ Release History
 master
 ------
 
+**Improvements**
+
+* [#207](https://github.com/socialcopsdev/camelot/issues/207) Add a plot type for Stream text edges and detected table areas. [#224](https://github.com/socialcopsdev/camelot/pull/224) by Vinayak Mehta.
+
+**Bugfixes**
+
+* [#217](https://github.com/socialcopsdev/camelot/issues/217) Fix IndexError when scale is large.
+
+**Documentation**
+
+* Add pdfplumber comparison and update Tabula (stream) comparison. Check out the [wiki page](https://github.com/socialcopsdev/camelot/wiki/Comparison-with-other-PDF-Table-Extraction-libraries-and-tools).
+
 0.4.1 (2018-12-05)
 ------------------
 

camelot/cli.py

@@ -138,7 +138,7 @@ def lattice(c, *args, **kwargs):
 @click.option('-c', '--col_close_tol', default=0, help='Tolerance parameter'
               ' used to combine text horizontally, to generate columns.')
 @click.option('-plot', '--plot_type',
-              type=click.Choice(['text', 'grid']),
+              type=click.Choice(['text', 'grid', 'contour', 'textedge']),
               help='Plot elements found on PDF page for visual debugging.')
 @click.argument('filepath', type=click.Path(exists=True))
 @pass_config

camelot/parsers/lattice.py

@@ -341,6 +341,7 @@ class Lattice(BaseParser):
         table._text = _text
         table._image = (self.image, self.table_bbox_unscaled)
         table._segments = (self.vertical_segments, self.horizontal_segments)
+        table._textedges = None
 
         return table
 

camelot/parsers/stream.py

@@ -263,6 +263,7 @@ class Stream(BaseParser):
         textedges.generate(textlines)
         # select relevant edges
         relevant_textedges = textedges.get_relevant()
+        self.textedges.extend(relevant_textedges)
         # guess table areas using textlines and relevant edges
         table_bbox = textedges.get_table_areas(textlines, relevant_textedges)
         # treat whole page as table area if no table areas found
@@ -272,6 +273,7 @@ class Stream(BaseParser):
         return table_bbox
 
     def _generate_table_bbox(self):
+        self.textedges = []
         if self.table_areas is not None:
             table_bbox = {}
             for area in self.table_areas:
@@ -378,6 +380,7 @@ class Stream(BaseParser):
         table._text = _text
         table._image = None
         table._segments = None
+        table._textedges = self.textedges
 
         return table
 

camelot/plotting.py

@@ -33,7 +33,10 @@ class PlotMethods(object):
         if not _HAS_MPL:
             raise ImportError('matplotlib is required for plotting.')
 
-        if table.flavor == 'stream' and kind in ['contour', 'joint', 'line']:
+        if table.flavor == 'lattice' and kind in ['textedge']:
+            raise NotImplementedError("Lattice flavor does not support kind='{}'".format(
+                                      kind))
+        elif table.flavor == 'stream' and kind in ['joint', 'line']:
             raise NotImplementedError("Stream flavor does not support kind='{}'".format(
                                       kind))
 
@@ -114,20 +117,82 @@ class PlotMethods(object):
         fig : matplotlib.fig.Figure
 
         """
-        img, table_bbox = table._image
+        try:
+            img, table_bbox = table._image
+            _FOR_LATTICE = True
+        except TypeError:
+            img, table_bbox = (None, {table._bbox: None})
+            _FOR_LATTICE = False
         fig = plt.figure()
         ax = fig.add_subplot(111, aspect='equal')
+
+        xs, ys = [], []
+        if not _FOR_LATTICE:
+            for t in table._text:
+                xs.extend([t[0], t[2]])
+                ys.extend([t[1], t[3]])
+                ax.add_patch(
+                    patches.Rectangle(
+                        (t[0], t[1]),
+                        t[2] - t[0],
+                        t[3] - t[1],
+                        color='blue'
+                    )
+                )
+
         for t in table_bbox.keys():
             ax.add_patch(
                 patches.Rectangle(
                     (t[0], t[1]),
                     t[2] - t[0],
                     t[3] - t[1],
-                    fill=None,
-                    edgecolor='red'
+                    fill=False,
+                    color='red'
                 )
             )
-        ax.imshow(img)
+            if not _FOR_LATTICE:
+                xs.extend([t[0], t[2]])
+                ys.extend([t[1], t[3]])
+                ax.set_xlim(min(xs) - 10, max(xs) + 10)
+                ax.set_ylim(min(ys) - 10, max(ys) + 10)
+
+        if _FOR_LATTICE:
+            ax.imshow(img)
+        return fig
+
+    def textedge(self, table):
+        """Generates a plot for relevant textedges.
+
+        Parameters
+        ----------
+        table : camelot.core.Table
+
+        Returns
+        -------
+        fig : matplotlib.fig.Figure
+
+        """
+        fig = plt.figure()
+        ax = fig.add_subplot(111, aspect='equal')
+        xs, ys = [], []
+        for t in table._text:
+            xs.extend([t[0], t[2]])
+            ys.extend([t[1], t[3]])
+            ax.add_patch(
+                patches.Rectangle(
+                    (t[0], t[1]),
+                    t[2] - t[0],
+                    t[3] - t[1],
+                    color='blue'
+                )
+            )
+        ax.set_xlim(min(xs) - 10, max(xs) + 10)
+        ax.set_ylim(min(ys) - 10, max(ys) + 10)
+
+        for te in table._textedges:
+            ax.plot([te.x, te.x],
+                    [te.y0, te.y1])
+
         return fig
 
     def joint(self, table):

docs/user/advanced.rst

@@ -41,8 +41,9 @@ You can specify the type of element you want to plot using the ``kind`` keyword
 - 'contour'
 - 'line'
 - 'joint'
+- 'textedge'
 
-.. note:: The last three plot types can only be used with :ref:`Lattice <lattice>`, i.e. when ``flavor='lattice'``.
+.. note:: 'line' and 'joint' can only be used with :ref:`Lattice <lattice>` and 'textedge' can only be used with :ref:`Stream <stream>`.
 
 Let's generate a plot for each type using this `PDF <../_static/pdf/foo.pdf>`__ as an example. First, let's get all the tables out.
 
@@ -143,6 +144,23 @@ Finally, let's plot all line intersections present on the table's PDF page.
     :alt: A plot of all line intersections on a PDF page
     :align: left
 
+textedge
+^^^^^^^^
+
+You can also visualize the textedges found on a page by specifying ``kind='textedge'``. To know more about what a "textedge" is, you can see pages 20, 35 and 40 of `Anssi Nurminen's master's thesis <http://dspace.cc.tut.fi/dpub/bitstream/handle/123456789/21520/Nurminen.pdf?sequence=3>`_.
+
+::
+
+    >>> camelot.plot(tables[0], kind='textedge')
+    >>> plt.show()
+
+.. figure:: ../_static/png/plot_textedge.png
+    :height: 674
+    :width: 1366
+    :scale: 50%
+    :alt: A plot of relevant textedges on a PDF page
+    :align: left
+
 Specify table areas
 -------------------
 

tests/test_plotting.py

@@ -29,12 +29,20 @@ def test_grid_plot():
 
 @pytest.mark.mpl_image_compare(
     baseline_dir="files/baseline_plots", remove_text=True)
-def test_contour_plot():
+def test_lattice_contour_plot():
     filename = os.path.join(testdir, "foo.pdf")
     tables = camelot.read_pdf(filename)
     return camelot.plot(tables[0], kind='contour')
 
 
+@pytest.mark.mpl_image_compare(
+    baseline_dir="files/baseline_plots", remove_text=True)
+def test_stream_contour_plot():
+    filename = os.path.join(testdir, "tabula/12s0324.pdf")
+    tables = camelot.read_pdf(filename, flavor='stream')
+    return camelot.plot(tables[0], kind='contour')
+
+
 @pytest.mark.mpl_image_compare(
     baseline_dir="files/baseline_plots", remove_text=True)
 def test_line_plot():
@@ -49,3 +57,11 @@ def test_joint_plot():
     filename = os.path.join(testdir, "foo.pdf")
     tables = camelot.read_pdf(filename)
     return camelot.plot(tables[0], kind='joint')
+
+
+@pytest.mark.mpl_image_compare(
+    baseline_dir="files/baseline_plots", remove_text=True)
+def test_textedge_plot():
+    filename = os.path.join(testdir, "tabula/12s0324.pdf")
+    tables = camelot.read_pdf(filename, flavor='stream')
+    return camelot.plot(tables[0], kind='textedge')