added image cropping tool

main
Brendan Howell 3 years ago
parent d94611313c
commit 36faee0258

@ -0,0 +1,144 @@
# a digital cake knife in the spirit of Hannah Höch
# cuts out composable contours from the herbarium scans
import glob
import os.path
import sqlite3
import cv2
import numpy as np
from PIL import Image
BLUR = 3
CANNY_THRESH_1 = 200
CANNY_THRESH_2 = 250
MASK_DILATE_ITER = 40
MASK_ERODE_ITER = 40
MASK_COLOR = (0.0,0.0,1.0) # In BGR format
src_imgs = glob.glob("specimen_img_raw/*")
db = sqlite3.connect("ratios.db")
dbc = db.cursor()
for src in src_imgs:
img_color = cv2.imread(src)
scalar = float(1000.0 / img_color.shape[1])
new_height = int(scalar * img_color.shape[0])
img_color = cv2.resize(img_color, (1000, new_height))
img_gray = cv2.imread(src, flags=cv2.IMREAD_GRAYSCALE)
img_gray = cv2.resize(img_gray, (1000, new_height))
# add some white around the edges so we have some space to rotate
img_color = cv2.copyMakeBorder(img_color,10,10,10,10,cv2.BORDER_CONSTANT, value=[255, 255, 255])
img_gray = cv2.copyMakeBorder(img_gray,10,10,10,10,cv2.BORDER_CONSTANT, value=[255])
blurred = cv2.GaussianBlur(img_gray, (9, 9), 0)
aperture = 5 # default is 3 but 5 or 7 are more sensitive
# most of this is ganked directly from this https://stackoverflow.com/questions/29313667/how-do-i-remove-the-background-from-this-kind-of-image
#-- Edge detection -------------------------------------------------------------------
edges = cv2.Canny(blurred, CANNY_THRESH_1, CANNY_THRESH_2, apertureSize=aperture)
edges = cv2.dilate(edges, None)
edges = cv2.erode(edges, None)
#-- Find contours in edges, sort by area ---------------------------------------------
contour_info = []
contours, _ = cv2.findContours(edges, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)
for c in contours:
contour_info.append((
c,
cv2.isContourConvex(c),
cv2.contourArea(c),
))
contour_info = sorted(contour_info, key=lambda c: c[2], reverse=True)
# filter out the accidental box contours - should be less than 85% of pixels
img_area = img_color.shape[0] * img_color.shape[1]
for cont in contour_info:
max_contour = cont
pixel_ratio = max_contour[2] / img_area
if pixel_ratio < 0.85:
test_img = img_color.copy()
c_rect = cv2.minAreaRect(max_contour[0])
box = cv2.boxPoints(c_rect)
box = np.int0(box)
cv2.drawContours(test_img, [max_contour[0]], -1, (255, 0, 0, 20), 3)
cv2.drawContours(test_img, [box], -1, (0, 255, 0), 3)
cv2.imwrite("test.png", test_img)
test_viewer = Image.open("test.png")
test_viewer.show()
if input("contour ok (y/n)?") == "y":
test_viewer.close()
break
test_viewer.close()
#-- Create empty mask, draw filled polygon on it corresponding to largest contour ----
# Mask is black, polygon is white
mask = np.zeros(edges.shape)
cv2.fillConvexPoly(mask, max_contour[0], (255))
#-- Smooth mask, then blur it --------------------------------------------------------
mask = cv2.dilate(mask, None, iterations=MASK_DILATE_ITER)
mask = cv2.erode(mask, None, iterations=MASK_ERODE_ITER)
mask = cv2.GaussianBlur(mask, (BLUR, BLUR), 0)
mask_stack = np.dstack([mask]*3) # Create 3-channel alpha mask
#-- Blend masked img into MASK_COLOR background --------------------------------------
mask_stack = mask_stack.astype('float32') / 255.0 # Use float matrices,
img_color = img_color.astype('float32') / 255.0 # for easy blending
# split image into channels
try:
c_red, c_green, c_blue = cv2.split(img_color)
except ValueError:
print("seems to be greyscale already...")
img_color = cv2.cvtColor(img_color, cv2.COLOR_GRAY2BGR)
c_red, c_green, c_blue = cv2.split(img_color)
# merge with mask got on one of a previous steps
img_a = cv2.merge((c_red, c_green, c_blue, mask.astype('float32') / 255.0))
# find bounding minimum bounding rect as that's what we want to rotate & save
rect = cv2.minAreaRect(max_contour[0])
box = cv2.boxPoints(rect)
box = np.int0(box)
width = int(rect[1][0])
height = int(rect[1][1])
# set up a new destination exactly the size of our ROI
src_pts = box.astype("float32")
dst_pts = np.array([[0, height-1],
[0, 0],
[width-1, 0],
[width-1, height-1]], dtype="float32")
# now rotate using warp which is more efficient and preserves pixels
M = cv2.getPerspectiveTransform(src_pts, dst_pts)
warped = cv2.warpPerspective(img_a, M, (width, height))
# save to disk
basename, ext = os.path.splitext(os.path.basename(src))
out_path = os.path.join("specimen_cutout", basename + ".png")
print("saving cropped cutout", out_path)
cv2.imwrite(out_path, warped*255)
# add to database
if height > width:
ratio = float(height) / width
else:
ratio = float(width) / height
try:
dbc.execute("INSERT INTO images VALUES (?, ?, ?, ?)", (ratio, width, height, out_path))
except sqlite3.IntegrityError as err:
print(err)
print("Trying db update instead.")
dbc.execute("UPDATE images SET (ratio, width, height) = (?, ?, ?) WHERE img_path = ?",
(ratio, width, height, out_path))
db.commit()
db.close()

@ -20,7 +20,7 @@ def find_image(rdf_doc):
return obj return obj
with open("barcode_cleaned.csv") as bcfile: with open("belgian_colony_data_all.csv") as bcfile:
for line in bcfile: for line in bcfile:
barcode = line.split(",")[0] barcode = line.split(",")[0]

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