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Fix more things

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This commit is contained in:
James R. Barlow
2023-11-19 23:51:27 -08:00
parent 2ca6e110ca
commit 0a07c0a44e
3 changed files with 49 additions and 51 deletions
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src/ocrmypdf/hocrtransform/__init__.py
+46 -49
View File
@@ -12,7 +12,7 @@ import argparse
import os
import re
from dataclasses import dataclass
from math import atan, cos, sin
from math import atan, cos, pi, sin
from pathlib import Path
from typing import Any, NamedTuple
from xml.etree import ElementTree
@@ -26,6 +26,7 @@ from ocrmypdf.hocrtransform.backends.pikepdf import PikepdfCanvas
from ocrmypdf.hocrtransform.backends.reportlab import (
ReportlabCanvas,
black,
blue,
cyan,
green,
inch,
@@ -121,6 +122,7 @@ class DebugRenderOptions:
render_paragraph_bbox: bool
render_baseline: bool
render_triangle: bool
render_line_bbox: bool
render_word_bbox: bool
@@ -173,8 +175,9 @@ class HocrTransform:
raise HocrTransformError("hocr file is missing page dimensions")
self.render_options = DebugRenderOptions(
render_baseline=True,
render_triangle=True,
render_word_bbox=False,
render_triangle=False,
render_line_bbox=False,
render_word_bbox=True,
render_paragraph_bbox=False,
)
@@ -354,42 +357,43 @@ class HocrTransform:
return
pxl_line_coords = self.element_coordinates(line)
line_box = self.pt_from_pixel(pxl_line_coords, bottomup=True)
line_height = line_box.y2 - line_box.y1
assert line_box.y2 > line_box.y1
# Baseline is a polynomial (usually straight line) in the coordinate system
# of the line
slope, pxl_intercept = self.baseline(line)
if abs(slope) < 0.005:
slope = 0.0
angle = atan(slope)
cos_a, sin_a = cos(angle), sin(angle)
intercept = pxl_intercept / self.dpi * inch
# Enter a new coordinate system with the linebox at the origin
canvas.push()
line_matrix = PdfMatrix().translated(line_box.x1, line_box.y1).rotated(-angle)
line_matrix = (
PdfMatrix().translated(line_box.x1, line_box.y1).rotated(-angle / pi * 180)
)
canvas.cm(*line_matrix.shorthand)
cos_a, sin_a = 1, 0
slope = 0
intercept = 0
cm_line_box = line_box.transform(line_matrix, inverse=True)
cm_line_height = cm_line_box.y2 - cm_line_box.y1
text = canvas.begin_text()
# Don't allow the font to break out of the bounding box. Division by
# cos_a accounts for extra clearance between the glyph's vertical axis
# on a sloped baseline and the edge of the bounding box.
fontsize = (line_height - abs(intercept)) / cos_a
fontsize = cm_line_height - abs(intercept)
text.set_font(fontname, fontsize)
if invisible_text or True:
text.set_render_mode(3) # Invisible (indicates OCR text)
# Intercept is normally negative. Subtracting it will raise the baseline
# above the bottom of the bounding box (y1). We're in page coordinates,
# origin bottom left, y2 > y1.
baseline_y1 = -intercept
# above the bottom of the bounding box (y1).
baseline_y1 = cm_line_box.y1 - intercept
self._do_debug_baseline(canvas, slope, cm_line_box, baseline_y1)
self._do_debug_line_bbox(canvas, cm_line_box)
self._do_debug_baseline(canvas, 0, cm_line_box, baseline_y1)
text.set_text_transform(1, 0, 0, 1, line_box.x1, baseline_y1)
canvas.set_fill_color(black) # text in black
@@ -399,12 +403,11 @@ class HocrTransform:
canvas,
fontname,
interword_spaces,
line_height,
cm_line_height,
line_matrix,
cm_line_box,
text,
fontsize,
baseline_y1,
elem,
)
canvas.draw_text(text)
@@ -420,7 +423,6 @@ class HocrTransform:
cm_line_box,
text,
fontsize,
baseline_y1,
elem,
):
elemtxt = self._get_element_text(elem).strip()
@@ -438,53 +440,47 @@ class HocrTransform:
# and paste. Do not remove space from last word in line, even
# though it would look better, because it will interfere with
# naive text extraction. \n does not work either.
elemtxt += ' '
space_width = canvas.string_width(' ', fontname, fontsize)
cm_box = Rect._make(
(
cm_box.x1,
cm_line_box.y1,
cm_box.x2, # + pdf.string_width(' ', fontname, line_height),
cm_box.x2,
cm_line_box.y2,
)
)
else:
space_width = 0
box_width = cm_box.x2 - cm_box.x1
font_width = canvas.string_width(elemtxt, fontname, fontsize)
font_width = canvas.string_width(elemtxt, fontname, fontsize) + space_width
# draw the bbox border
self._do_debug_word_triangle(canvas, cm_box)
self._do_debug_bbox(canvas, line_height, cm_line_box, cm_box, box_width)
self._do_debug_word_bbox(canvas, line_height, cm_line_box, cm_box, box_width)
# Adjust relative position of cursor
# This is equivalent to:
# text.setTextOrigin(pt.x1, self.height - line_box.y2)
# but the former generates a full text reposition matrix (Tm) in the
# content stream while this issues a "offset" (Td) command.
# .move_cursor() is relative to start of the text line, where the
# "text line" means whatever reportlab defines it as. Do not use
# use .getCursor(), since move_cursor() rather unintuitively plans
# its moves relative to .getStartOfLine().
# For skewed lines, in the text transform we set up a rotated
# coordinate system, so we don't have to account for the
# incremental offset. Surprisingly most PDF viewers can handle this.
if 0:
cursor = text.get_start_of_line()
dx = box.x1 - cursor[0]
dy = baseline_y1 - cursor[1]
text.move_cursor(dx, dy)
text.set_text_transform(
1,
0,
0,
1,
cm_box.x1,
cm_line_box.y1,
)
text.set_text_transform(1, 0, 0, 1, cm_box.x1, cm_line_box.y1)
# If reportlab tells us this word is 0 units wide, our best seems
# to be to suppress this text
if font_width > 0:
text.set_horiz_scale(100 * box_width / font_width)
text.show(elemtxt)
text.show((elemtxt + ' ') if interword_spaces else elemtxt)
def _do_debug_line_bbox(self, canvas, line_box):
if not self.render_options.render_line_bbox: # pragma: no cover
return
canvas.push()
canvas.set_dashes()
canvas.set_stroke_color(blue)
canvas.set_line_width(0.15)
canvas.rect(
line_box.x1,
line_box.y1,
line_box.x2 - line_box.x1,
line_box.y2 - line_box.y1,
fill=0,
)
canvas.pop()
def _do_debug_word_triangle(
self,
@@ -503,7 +499,7 @@ class HocrTransform:
canvas.line(cm_box.x1, cm_box.y1, cm_box.x1, cm_box.y2) # rise
canvas.pop()
def _do_debug_bbox(self, canvas, line_height, cm_line_box, cm_box, box_width):
def _do_debug_word_bbox(self, canvas, line_height, cm_line_box, cm_box, box_width):
if not self.render_options.render_word_bbox: # pragma: no cover
return
canvas.push()
@@ -526,7 +522,8 @@ class HocrTransform:
line_box.x1,
baseline_y1,
line_box.x2,
self.polyval((-slope, baseline_y1), line_box.x2 - line_box.x1),
baseline_y1,
# self.polyval((-slope, baseline_y1), line_box.x2 - line_box.x1),
)
src/ocrmypdf/hocrtransform/backends/pikepdf.py
+2 -1
View File
@@ -176,7 +176,8 @@ class ContentStreamBuilder:
def show_text(self, text: str):
"""Show text."""
inst = ContentStreamInstruction([[text.encode("utf-16be")]], Operator("TJ"))
encoded = text.encode("utf-16be")
inst = ContentStreamInstruction([[encoded]], Operator("TJ"))
self._instructions.append(inst)
return self
src/ocrmypdf/hocrtransform/backends/reportlab.py
+1 -1
View File
@@ -10,7 +10,7 @@ with warnings.catch_warnings():
warnings.filterwarnings(
'ignore', category=DeprecationWarning, message=r".*load_module.*"
)
from reportlab.lib.colors import black, cyan, green, magenta, red
from reportlab.lib.colors import black, blue, cyan, green, magenta, red
from reportlab.lib.units import inch
from reportlab.pdfgen.canvas import Canvas
from reportlab.pdfgen.textobject import PDFTextObject