diff --git a/tests/test_scans.py b/tests/test_scans.py
index 5b61b30be5ecd090148589fe60acdf056279e856..79a4e7aaab2bcca76b8f09cd578f62f712ed94b5 100644
--- a/tests/test_scans.py
+++ b/tests/test_scans.py
@@ -291,15 +291,15 @@ def test_realign_image(datadir, file_name):
test_file = os.path.join(datadir, dir_name, file_name)
test_image = np.array(PIL.Image.open(test_file))
- correct_corner_markers = [(58, 58), (1180, 58), (58, 1694), (1180, 1694)]
+ correct_corner_markers = [(59, 59), (1181, 59), (59, 1694), (1181, 1694)]
result_image, result_corner_markers = scans.realign_image(test_image)
assert result_corner_markers is not None
for i in range(4):
diff = np.absolute(np.subtract(correct_corner_markers[i], result_corner_markers[i]))
- assert diff[0] < epsilon
- assert diff[1] < epsilon
+ assert diff[0] <= epsilon
+ assert diff[1] <= epsilon
def test_incomplete_reference_realign_image(datadir):
diff --git a/zesje/api/exams.py b/zesje/api/exams.py
index a1c449a05bd1ad5d5a1f50a75c7e3698d66114e5..83dd18b52229ab84363cd29a877c4cb832c34f31 100644
--- a/zesje/api/exams.py
+++ b/zesje/api/exams.py
@@ -9,14 +9,9 @@ from flask_restful import Resource, reqparse
from werkzeug.datastructures import FileStorage
from sqlalchemy.orm import selectinload
-from ..pdf_generation import generate_pdfs, output_pdf_filename_format, join_pdfs, page_is_size
+from ..pdf_generation import PAGE_FORMATS, generate_pdfs, output_pdf_filename_format, join_pdfs, page_is_size
from ..database import db, Exam, ExamWidget, Submission
-PAGE_FORMATS = {
- "A4": (595.276, 841.89),
- "US letter": (612, 792),
-}
-
def _get_exam_dir(exam_id):
return os.path.join(
diff --git a/zesje/pdf_generation.py b/zesje/pdf_generation.py
index 09bf9641bd13e631eb02a163f69ef2959b7955d6..e4b3c2ece43bfb237c09cdfc05f2bca60507c336 100644
--- a/zesje/pdf_generation.py
+++ b/zesje/pdf_generation.py
@@ -10,6 +10,19 @@ from reportlab.pdfgen import canvas
output_pdf_filename_format = '{0:05d}.pdf'
+# the size of the markers in points
+MARKER_FORMAT = {
+ "margin": 10 * mm,
+ "marker_line_length": 8 * mm,
+ "marker_line_width": 1 * mm,
+ "bar_length": 40 * mm
+}
+
+PAGE_FORMATS = {
+ "A4": (595.276, 841.89),
+ "US letter": (612, 792),
+}
+
def generate_pdfs(exam_pdf_file, exam_id, copy_nums, output_paths, id_grid_x,
id_grid_y, datamatrix_x, datamatrix_y, cb_data=None):
@@ -318,15 +331,14 @@ def _add_corner_markers_and_bottom_bar(canv, pagesize):
"""
page_width = pagesize[0]
page_height = pagesize[1]
- margin = 10 * mm
- marker_line_length = 8 * mm
- bar_length = 40 * mm
+ marker_line_length = MARKER_FORMAT["marker_line_length"]
+ bar_length = MARKER_FORMAT["bar_length"]
# Calculate coordinates offset from page edge
- left = margin
- bottom = margin
- right = page_width - margin
- top = page_height - margin
+ left = MARKER_FORMAT["margin"]
+ bottom = MARKER_FORMAT["margin"]
+ right = page_width - MARKER_FORMAT["margin"]
+ top = page_height - MARKER_FORMAT["margin"]
# Calculate start and end coordinates of bottom bar
bar_start = page_width / 2 - bar_length / 2
diff --git a/zesje/scans.py b/zesje/scans.py
index 8addf7ab033a93d3809734760ae5988dec36ec45..9fbee694be950c006c6e24d57fe61345ee16e7a8 100644
--- a/zesje/scans.py
+++ b/zesje/scans.py
@@ -19,6 +19,8 @@ from .images import guess_dpi, get_box, fix_corner_markers
from .factory import make_celery
from .pregrader import add_feedback_to_solution
+from .pdf_generation import MARKER_FORMAT, PAGE_FORMATS
+
ExtractedBarcode = namedtuple('ExtractedBarcode', ['token', 'copy', 'page'])
ExamMetadata = namedtuple('ExamMetadata', ['token', 'barcode_coords'])
@@ -791,7 +793,7 @@ def check_corner_keypoints(image_array, keypoints):
def realign_image(image_array, keypoints=None,
- reference_keypoints=None):
+ reference_keypoints=None, page_format="A4"):
"""
Transform the image so that the keypoints match the reference.
@@ -815,7 +817,7 @@ def realign_image(image_array, keypoints=None,
New keypoints properly aligned.
"""
- if(keypoints is None):
+ if(not keypoints):
keypoints = find_corner_marker_keypoints(image_array)
check_corner_keypoints(image_array, keypoints)
@@ -823,8 +825,10 @@ def realign_image(image_array, keypoints=None,
keypoints = fix_corner_markers(keypoints, image_array.shape)
# use standard keypoints if no custom ones are provided
- if (reference_keypoints is None):
- reference_keypoints = [(59, 59), (1179, 59), (59, 1693), (1179, 1693)]
+ if (not reference_keypoints):
+ # reference_keypoints = [(59, 59), (1179, 59), (59, 1693), (1179, 1693)]
+ dpi = guess_dpi(image_array)
+ reference_keypoints = generate_perfect_corner_markers(page_format, dpi)
if (len(reference_keypoints) != 4):
# this function assumes that the template has the same dimensions as the input image
@@ -848,3 +852,15 @@ def realign_image(image_array, keypoints=None,
return_keypoints = fix_corner_markers(return_keypoints, return_image.shape)
return return_image, return_keypoints
+
+
+def generate_perfect_corner_markers(format="A4", dpi=200):
+ left_x = MARKER_FORMAT["margin"]/72 * dpi
+ top_y = MARKER_FORMAT["margin"]/72 * dpi
+ right_x = (PAGE_FORMATS[format][0] - MARKER_FORMAT["margin"])/72 * dpi
+ bottom_y = (PAGE_FORMATS[format][1] - MARKER_FORMAT["margin"])/72 * dpi
+
+ return [(left_x, top_y),
+ (right_x, top_y),
+ (left_x, bottom_y),
+ (right_x, bottom_y)]