'numpy.ndarray' object has no attribute 'split' - opencv

I have read that AttributeError: 'numpy.ndarray' object has no attribute 'split' and Why is pytesseract causing AttributeError: 'NoneType' object has no attribute 'bands'? but found no soultion to my answer.
I am following this article https://www.pyimagesearch.com/2018/09/17/opencv-ocr-and-text-recognition-with-tesseract/#comment-481113. This shows how can we detect and extract text on images using tesseacact. I have insalled everything on my system but when i run the code i receive the following error :
Traceback (most recent call last):
File "text_recognition.py", line 157, in <module>
text = pytesseract.image_to_string(roi, config=config)
File "C:\Users\prince.bhatia\AppData\Local\Programs\Python\Python36\lib\site-p
ackages\pytesseract\pytesseract.py", line 104, in image_to_string
if len(image.split()) == 4:
AttributeError: 'numpy.ndarray' object has no attribute 'split'
below is my complete code:
# USAGE
# python text_recognition.py --east frozen_east_text_detection.pb --image images/example_01.jpg
# python text_recognition.py --east frozen_east_text_detection.pb --image images/example_04.jpg --padding 0.05
# import the necessary packages
from imutils.object_detection import non_max_suppression
import numpy as np
import pytesseract
import argparse
import cv2
def decode_predictions(scores, geometry):
# grab the number of rows and columns from the scores volume, then
# initialize our set of bounding box rectangles and corresponding
# confidence scores
(numRows, numCols) = scores.shape[2:4]
rects = []
confidences = []
# loop over the number of rows
for y in range(0, numRows):
# extract the scores (probabilities), followed by the
# geometrical data used to derive potential bounding box
# coordinates that surround text
scoresData = scores[0, 0, y]
xData0 = geometry[0, 0, y]
xData1 = geometry[0, 1, y]
xData2 = geometry[0, 2, y]
xData3 = geometry[0, 3, y]
anglesData = geometry[0, 4, y]
# loop over the number of columns
for x in range(0, numCols):
# if our score does not have sufficient probability,
# ignore it
if scoresData[x] < args["min_confidence"]:
continue
# compute the offset factor as our resulting feature
# maps will be 4x smaller than the input image
(offsetX, offsetY) = (x * 4.0, y * 4.0)
# extract the rotation angle for the prediction and
# then compute the sin and cosine
angle = anglesData[x]
cos = np.cos(angle)
sin = np.sin(angle)
# use the geometry volume to derive the width and height
# of the bounding box
h = xData0[x] + xData2[x]
w = xData1[x] + xData3[x]
# compute both the starting and ending (x, y)-coordinates
# for the text prediction bounding box
endX = int(offsetX + (cos * xData1[x]) + (sin * xData2[x]))
endY = int(offsetY - (sin * xData1[x]) + (cos * xData2[x]))
startX = int(endX - w)
startY = int(endY - h)
# add the bounding box coordinates and probability score
# to our respective lists
rects.append((startX, startY, endX, endY))
confidences.append(scoresData[x])
# return a tuple of the bounding boxes and associated confidences
return (rects, confidences)
# construct the argument parser and parse the arguments
ap = argparse.ArgumentParser()
ap.add_argument("-i", "--image", type=str,
help="path to input image")
ap.add_argument("-east", "--east", type=str,
help="path to input EAST text detector")
ap.add_argument("-c", "--min-confidence", type=float, default=0.5,
help="minimum probability required to inspect a region")
ap.add_argument("-w", "--width", type=int, default=320,
help="nearest multiple of 32 for resized width")
ap.add_argument("-e", "--height", type=int, default=320,
help="nearest multiple of 32 for resized height")
ap.add_argument("-p", "--padding", type=float, default=0.0,
help="amount of padding to add to each border of ROI")
args = vars(ap.parse_args())
# load the input image and grab the image dimensions
image = cv2.imread(args["image"])
orig = image.copy()
(origH, origW) = image.shape[:2]
# set the new width and height and then determine the ratio in change
# for both the width and height
(newW, newH) = (args["width"], args["height"])
rW = origW / float(newW)
rH = origH / float(newH)
# resize the image and grab the new image dimensions
image = cv2.resize(image, (newW, newH))
(H, W) = image.shape[:2]
# define the two output layer names for the EAST detector model that
# we are interested -- the first is the output probabilities and the
# second can be used to derive the bounding box coordinates of text
layerNames = [
"feature_fusion/Conv_7/Sigmoid",
"feature_fusion/concat_3"]
# load the pre-trained EAST text detector
print("[INFO] loading EAST text detector...")
net = cv2.dnn.readNet(args["east"])
# construct a blob from the image and then perform a forward pass of
# the model to obtain the two output layer sets
blob = cv2.dnn.blobFromImage(image, 1.0, (W, H),
(123.68, 116.78, 103.94), swapRB=True, crop=False)
net.setInput(blob)
(scores, geometry) = net.forward(layerNames)
# decode the predictions, then apply non-maxima suppression to
# suppress weak, overlapping bounding boxes
(rects, confidences) = decode_predictions(scores, geometry)
boxes = non_max_suppression(np.array(rects), probs=confidences)
# initialize the list of results
results = []
# loop over the bounding boxes
for (startX, startY, endX, endY) in boxes:
# scale the bounding box coordinates based on the respective
# ratios
startX = int(startX * rW)
startY = int(startY * rH)
endX = int(endX * rW)
endY = int(endY * rH)
# in order to obtain a better OCR of the text we can potentially
# apply a bit of padding surrounding the bounding box -- here we
# are computing the deltas in both the x and y directions
dX = int((endX - startX) * args["padding"])
dY = int((endY - startY) * args["padding"])
# apply padding to each side of the bounding box, respectively
startX = max(0, startX - dX)
startY = max(0, startY - dY)
endX = min(origW, endX + (dX * 2))
endY = min(origH, endY + (dY * 2))
# extract the actual padded ROI
roi = orig[startY:endY, startX:endX]
print(roi)
# in order to apply Tesseract v4 to OCR text we must supply
# (1) a language, (2) an OEM flag of 4, indicating that the we
# wish to use the LSTM neural net model for OCR, and finally
# (3) an OEM value, in this case, 7 which implies that we are
# treating the ROI as a single line of text
config = ("-l eng --oem 1 --psm 7")
text = pytesseract.image_to_string(roi, config=config)#here i cam receiving error
# add the bounding box coordinates and OCR'd text to the list
# of results
results.append(((startX, startY, endX, endY), text))
# sort the results bounding box coordinates from top to bottom
results = sorted(results, key=lambda r:r[0][1])
# loop over the results
for ((startX, startY, endX, endY), text) in results:
# display the text OCR'd by Tesseract
print("OCR TEXT")
print("========")
print("{}\n".format(text))
# strip out non-ASCII text so we can draw the text on the image
# using OpenCV, then draw the text and a bounding box surrounding
# the text region of the input image
text = "".join([c if ord(c) < 128 else "" for c in text]).strip()
output = orig.copy()
cv2.rectangle(output, (startX, startY), (endX, endY),
(0, 0, 255), 2)
cv2.putText(output, text, (startX, startY - 20),
cv2.FONT_HERSHEY_SIMPLEX, 1.2, (0, 0, 255), 3)
# show the output image
cv2.imshow("Text Detection", output)
cv2.waitKey(0)

Related

How to accurately detect and localize car fuse?

Currently I'm working on a project, where I need to measure the width of car fuse wire. In order to achieve that I need to detect and localize the fuse on the image. fuse_image
My plan is to find bounding rectangle region with the fuse and then search for a wire contours in fixed position of that region.fuse_contours
I have already tried ORB, BRISK feature based template matching, but the results were not acceptable. Maybe anyone can suggest some possible methods to solve this task?
We can start the problem by applying Canny operation to see the features of the image. Result is:
The aim is to calculate the width. Therefore we only need the left and right outer length of the image. We don't need inner lines. To remove the inner features we can smooth the image.
How do we accurately calculate the width? What part of the features can we take as an reference? If we consider the base? The base features are:
How do we find the base feature coordinates?
Blue point is the one with the highest y coordinate value
Red point is the one with the highest x coordinate value
For all detected line coordinates, we need to find the highest y coordinate value with the corresponding x coordinate value. We need to find the highest x coordinate value with the corresponding y value.
For detecting line coordinates we can use fast line detector. Result will be:
We can calculate the euclidian-distance, which will be: 146.49 pixel
The idea is based on the finding the base and then calculating the euclidean-distance.
Update
The orientation of the fuse can be random.
First, we need to get the fuse part of the image.
Second, we need to get the canny features (or any other filtering method)
At this point we need to find the left (blue-dot) and right (red-dot) part of the fuse:
If we connect them:
We will have an approximate length of the fuse.
So How do we find the left and right parts of the fuse?
Finding left part:
1. From the current x1, x2 tuples
2. If min(x1, x2) < x_min
3. x_min = min(x1, x2)
Finding right part:
1. From the current x1, x2 tuples
2. If max(x1, x2) > x_max
3. x_max = max(x1, x2)
This is my idea for approaching the problem. You can modify for better results.
Code:
# Load libraries
import cv2
import numpy as np
# Load the image
img = cv2.imread("E8XlZ.jpg")
# Get the image dimension
(h, w) = img.shape[:2]
# Convert to hsv
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
# Get the binary-mask
msk = cv2.inRange(hsv, np.array([0, 24, 161]), np.array([77, 255, 217]))
# Display the mask
cv2.imshow("msk", msk)
cv2.waitKey(0)
# Smooth the image
gauss = cv2.GaussianBlur(msk, (21, 21), 0)
# Canny features
cny = cv2.Canny(gauss, 50, 200)
# Display canny features
cv2.imshow("cny", cny)
cv2.waitKey(0)
# Initialize line-detector
lns = cv2.ximgproc.createFastLineDetector().detect(cny)
# Initialize temporary variables
x_min, x_max, y_min, y_max = w, 0, 0, 0
# Detect the lines
for line in lns:
# Get current coordinates
x1 = int(line[0][0])
y1 = int(line[0][1])
x2 = int(line[0][2])
y2 = int(line[0][3])
# Get maximum coordinates
if max(x1, x2) > x_max:
x_max = max(x1, x2)
y_max = y1 if x_max == x1 else y2
if min(x1, x2) < x_min:
x_min = min(x1, x2)
y_min = y1 if x_min == x1 else y2
# Draw the points
cv2.circle(img, (x_min, int((y_min + y_max)/2)), 3, (255, 0, 0), 5)
cv2.circle(img, (x_max, int((y_min + y_max)/2)), 3, (0, 0, 255), 5)
# Write coordinates to the console
print("Coordinates: ({}, {})->({}, {})".format(x_min, int((y_min + y_max)/2), x_max, int((y_min + y_max)/2)))
# Draw the minimum and maximum coordinates
cv2.line(img, (x_min, int((y_min + y_max)/2)), (x_max, int((y_min + y_max)/2)), (0, 255, 0), 5)
# Calculate the euclidean distance
pt1 = np.array((x_min, int((y_min + y_max)/2)))
pt2 = np.array((x_max, int((y_min + y_max)/2)))
dist = np.linalg.norm(pt1 - pt2)
print("Result: %.2f pixel" % dist)
# Display the result
cv2.imshow("img", img)
cv2.waitKey(0)

How to test OpenCV DNN module accuracy? It does not predict correct detections for YOLOv3. Whereas Darknet detector detects correctly

OpenCV DNN module does not predict correct detections for YOLOv3. Whereas the Darknet detector detects correctly.
System information (version)
OpenCV => 4.2.1 and 4.4.x
Operating System / Platform => Ubuntu 18.04 64Bit
I tested results with compiled OpenCV from source code and I tried with pre-built opencv-python also but OpenCV DNN detects wrong objects.
Whereas Darknet detector detects correctly.
Correct detection with darknet detector:
Wrong detection with OpenCV DNN module:
YOLOv3 network and model weights are from https://github.com/AlexeyAB/darknet
modelWeights: yolov3.weights
modelConfiguration: yolov3.cfg
ClassesFile: coco.names
Detailed description
Please see the output images at the link appended below. (correct detection with darknet detector)
compared with the wrong detection (with OpenCV DNN)
Output images available in this Google Drive link.
The above link includes test-images also for steps to test
# The following code is partial to demonstrate steps
net = cv.dnn.readNetFromDarknet(modelConfiguration, modelWeights)
layerNames = net.getLayerNames()
layerNames = [layerNames[i[0] - 1] for i in net.getUnconnectedOutLayers()]
# construct a blob from the input frame and then perform a forward pass of the YOLO object detector,
# giving us our bounding boxes and associated probabilities
blob = cv2.dnn.blobFromImage(frame, 1 / 255.0, (416, 416),
swapRB=True, crop=False)
net.setInput(blob)
layerOutputs = net.forward(layerNames)
# initialize our lists of detected bounding boxes, confidences,
# and class IDs, respectively
boxes = []
confidences = []
classIDs = []
# loop over each of the layer outputs
for output in layerOutputs:
# loop over each of the detections
for detection in output:
# extract the class ID and confidence (i.e., probability)
# of the current object detection
scores = detection[5:]
classID = np.argmax(scores)
confidence = scores[classID]
# filter out weak predictions by ensuring the detected
# probability is greater than the minimum probability
if confidence > args["confidence"]:
# scale the bounding box coordinates back relative to
# the size of the image, keeping in mind that YOLO
# actually returns the center (x, y)-coordinates of
# the bounding box followed by the boxes' width and
# height
box = detection[0:4] * np.array([W, H, W, H])
(centerX, centerY, width, height) = box.astype("int")
# use the center (x, y)-coordinates to derive the top
# and and left corner of the bounding box
x = int(centerX - (width / 2))
y = int(centerY - (height / 2))
# update our list of bounding box coordinates,
# confidences, and class IDs
boxes.append([x, y, int(width), int(height)])
confidences.append(float(confidence))
classIDs.append(classID)
# apply non-maxima suppression to suppress weak, overlapping
# bounding boxes
idxs = cv2.dnn.NMSBoxes(boxes, confidences, args["confidence"], args["threshold"])
dets = []
if len(idxs) > 0:
# loop over the indexes we are keeping
for i in idxs.flatten():
(x, y) = (boxes[i][0], boxes[i][1])
(w, h) = (boxes[i][2], boxes[i][3])
dets.append([x, y, x+w, y+h, confidences[i]])
if len(boxes) > 0:
i = int(0)
for box in boxes:
# extract the bounding box coordinates
(x, y) = (int(box[0]), int(box[1]))
(w, h) = (int(box[2]), int(box[3]))
# draw a bounding box rectangle and label on the image
# color = [int(c) for c in COLORS[classIDs[i]]]
# cv2.rectangle(frame, (x, y), (x + w, y + h), color, 2)
color = [int(c) for c in COLORS[indexIDs[i] % len(COLORS)]]
cv2.rectangle(frame, (x, y), (w, h), color, 2)
cv2.putText(frame, text, (x, y - 5), cv2.FONT_HERSHEY_SIMPLEX, 0.75, color, 2)# 1.0 0.5, color, 2)
i += 1
cv2.imwrite("detection-output.jpg", frame)
i think your detection is correct, since all of your labels is car, the problem is the text you have in this line:
cv2.putText(frame, text, (x, y - 5), cv2.FONT_HERSHEY_SIMPLEX, 0.75, color, 2)
you should put the class name in the text but i cant find where the text is defined. your code should be like this :
cv2.putText(frame, classes[class_ids[index]], (x + 5, y + 20), cv2.FONT_HERSHEY_COMPLEX_SMALL, 1, colors,2)
but in my experience , darknet has better detection than opencv dnn.

YOLO object detection opencv drawing a lot of rectangles

I have collected images of S9 phones, added labels with labellmg and trained for a few hours in google colab. I had minimal loss so I thought it is enough. I only selected the rectangles where the phone is displayed and nothing else. What I dont understand is, it draws a lot of rectangles on the phone. I only want 1 or 2 rectangles drawn on the phone itself. Did I do something wrong?
def detect_img(self, img):
blob = cv2.dnn.blobFromImage(img, 0.00392 ,(416,416), (0,0,0), True, crop=False)
input_img = self.net.setInput(blob)
output = self.net.forward(self.output)
height, width, channel = img.shape
boxes = []
trusts = []
class_ids = []
for out in output:
for detect in out:
total_scores = detect[5:]
class_id = np.argmax(total_scores)
trust_factor = total_scores[class_id]
if trust_factor > 0.5:
x_center = int(detect[0] * width)
y_center = int(detect[1] * height)
w = int(detect[2] * width)
h = int(detect[3] * height)
x = int(x_center - w / 2)
y = int(x_center - h / 2)
boxes.append([x,y,w,h])
trusts.append(float(trust_factor))
class_ids.append(class_id)
cv2.rectangle(img, (x_center,y_center), (x + w, y + h), (0,255,0), 2)
When I set the trust_factor to 0.8, a lot of the rectangles are gone but there are still rectangles outside the phone, while I only selected the phone itself in labellmg and not the background.
You can use function "non maximum suppression" that it removes rectangles which have less score. I put a code for NMS
def NMS(boxes, overlapThresh = 0.4):
# Return an empty list, if no boxes given
if len(boxes) == 0:
return []
x1 = boxes[:, 0] # x coordinate of the top-left corner
y1 = boxes[:, 1] # y coordinate of the top-left corner
x2 = boxes[:, 2] # x coordinate of the bottom-right corner
y2 = boxes[:, 3] # y coordinate of the bottom-right corner
# Compute the area of the bounding boxes and sort the bounding
# Boxes by the bottom-right y-coordinate of the bounding box
areas = (x2 - x1 + 1) * (y2 - y1 + 1) # We add 1, because the pixel at the start as well as at the end counts
# The indices of all boxes at start. We will redundant indices one by one.
indices = np.arange(len(x1))
for i,box in enumerate(boxes):
# Create temporary indices
temp_indices = indices[indices!=i]
# Find out the coordinates of the intersection box
xx1 = np.maximum(box[0], boxes[temp_indices,0])
yy1 = np.maximum(box[1], boxes[temp_indices,1])
xx2 = np.minimum(box[2], boxes[temp_indices,2])
yy2 = np.minimum(box[3], boxes[temp_indices,3])
# Find out the width and the height of the intersection box
w = np.maximum(0, xx2 - xx1 + 1)
h = np.maximum(0, yy2 - yy1 + 1)
# compute the ratio of overlap
overlap = (w * h) / areas[temp_indices]
# if the actual boungding box has an overlap bigger than treshold with any other box, remove it's index
if np.any(overlap) > treshold:
indices = indices[indices != i]
#return only the boxes at the remaining indices
return boxes[indices].astype(int)

Segmenting products on the shelf

I am trying to detect edges from the products on a shelf using histogram projections. But I am stuck at 2 levels.
The challenges that I m facing are:
How to get the longest non shelf segment from the image i.e Detect the width of the widest product on the shelf from the available one.
How to achieve morphological reconstruction using custom markers.To eliminate
all small horizontal segments, I am generating 2 markers which can be seen in 'markers.png' (Attached). With them, I am calculating the minimum of the reconstruction outputs from both the markers.
Need assistance on this.
Thanks a lot
Below is my python code for the same.
Below is my python code
********************************************************************************
import numpy as np
import cv2 as cv
from matplotlib import pyplot as plt
import math
# Read the input image
img = cv.imread('C:\\Users\\672059\\Desktop\\p2.png')
# Converting from BGR to RGB. Default is BGR.
# img_rgb = cv.cvtColor(img, cv.COLOR_BGR2RGB)
# Resize the image to 150,150
img_resize = cv.resize(img, (150, 150))
# Get the dimensions of the image
img_h, img_w, img_c = img_resize.shape
# Split the image on channels
red = img[:, :, 0]
green = img[:, :, 1]
blue = img[:, :, 2]
# Defining a vse for erosion
vse = np.ones((img_h, img_w), dtype=np.uint8)
# Morphological Erosion for red channel
red_erode = cv.erode(red, vse, iterations=1)
grad_red = cv.subtract(red, red_erode)
# Morphological Erosion for green channel
green_erode = cv.erode(green, vse, iterations=1)
grad_green = cv.subtract(green, green_erode)
# Morphological Erosion for blue channel
blue_erode = cv.erode(blue, vse, iterations=1)
grad_blue = cv.subtract(blue, blue_erode)
# Stacking the individual channels into one processed image
grad = [grad_red, grad_green, grad_blue]
retrieved_img = np.stack(grad, axis=-1)
retrieved_img = retrieved_img.astype(np.uint8)
retrieved_img_gray = cv.cvtColor(retrieved_img, cv.COLOR_RGB2GRAY)
plt.title('Figure 1')
plt.imshow(cv.bitwise_not(retrieved_img_gray), cmap=plt.get_cmap('gray'))
plt.show()
# Hough Transform of the image to get the longest non shelf boundary from the image!
edges = cv.Canny(retrieved_img_gray, 127, 255)
minLineLength = img_w
maxLineGap = 10
lines = cv.HoughLinesP(edges, 1, np.pi/180, 127, minLineLength=1, maxLineGap=1)
temp = img.copy()
l = []
for x in range(0, len(lines)):
for x1, y1, x2, y2 in lines[x]:
cv.line(temp, (x1, y1), (x2, y2), (0, 255, 0), 2)
d = math.sqrt((x2-x1)**2 + (y2-y1)**2)
l.append(d)
# Defining a hse for erosion
hse = np.ones((1, 7), dtype=np.uint8)
opening = cv.morphologyEx(retrieved_img_gray, cv.MORPH_OPEN, hse)
plt.title('Figure 2')
plt.subplot(1, 2, 1), plt.imshow(img)
plt.subplot(1, 2, 2), plt.imshow(cv.bitwise_not(opening), 'gray')
plt.show()
# Dilation with disk shaped structuring element
horizontal_size = 7
horizontalstructure = cv.getStructuringElement(cv.MORPH_ELLIPSE, (horizontal_size, 1))
dilation = cv.dilate(opening, horizontalstructure)
plt.title('Figure 3')
plt.imshow(cv.bitwise_not(dilation), 'gray')
plt.show()
# Doing canny edge on dilated image
edge = cv.Canny(dilation, 127, 255)
plt.title('Figure 4')
plt.imshow(edges, cmap='gray')
plt.show()
h_projection = edge.sum(axis=1)
print(h_projection)
plt.title('Projection')
plt.plot(h_projection)
plt.show()
listing = []
for i in range(1, len(h_projection)-1):
if h_projection[i-1] == 0 and h_projection[i] == 0:
listing.append(dilation[i])
listing.append(dilation[i-1])
a = np.array([np.array(b) for b in l])
h = len(l)
_, contours, _ = cv.findContours(a, cv.RETR_EXTERNAL, cv.CHAIN_APPROX_SIMPLE)
x, y, w, h = cv.boundingRect(contours[0])
y = y + i - h
cv.rectangle(img, (x, y), (x + w, y + h), (255, 0, 0), 2)
l.clear()
plt.imshow(img)
plt.show()
# Generating a mask
black_bg = np.ones([img_h, img_w], dtype=np.uint8)
# Clone the black bgd image
left = black_bg.copy()
right = black_bg.copy()
# Taking 10% of the image width
ten = int(0.1 * img_w)
left[:, 0:ten+1] = 0
right[:, img_w-ten:img_w+1] = 0
plt.title('Figure 4')
plt.subplot(121), plt.imshow(left, 'gray')
plt.subplot(122), plt.imshow(right, 'gray')
plt.show()
# Marker = left and right. Mask = dilation
mask = dilation
marker_left = left
marker_right = right
********************************************************************************
markers.png link: https://i.stack.imgur.com/45WJ6.png
********************************************************************************
Based on you input image, I would :
take a picture of an empty fridge
then compare the current image with the empty one.
play with morphological operations
get connected components > size N
If you can't take a empty fridge image:
segment the shelves (threshold white parts)
undo do the rotation of the image by using image moments of the shelves
for each shelve:
Threshold on saturation
Do a vertical projection
Count maxima.
Tresholded:
Erode-dilate:
Connected componens (width > 10 * height + > minsize):
And you have shelves.
Now take the average Y form each shelf and cut the original image in pieces:
Dither to 8 colors:
and threshold:
Connected components (h>1.5*w, minsize... this is hard here, I played with it :)

How to read an analogue gauge using Open CV

I'm interested in trying to read an analog gauge using a Raspberry PI and Open CV. I've only really messed with face detection in opencv, so I don't even know where to begin. Any ideas, starting points?
You can detect circles with HoughCircles method and detect lines with HoughLinesP method of with opencv lib in Python. After detecting these, you can find out the value of the gauge from the line's position via trigonometry.
You can see the sample code in python. It basically does these:
Read image with imread method.
turn it in to gray with cvtColor.
Find out the circles' center x,y coordinates and radius with HoughCircles, these method has some parameter that can be tweaked.
Detect the lines with HoughLinesP method again parameters should be tweaked.
Calculate the value, considering max value, min value on the gauge and angle interval of the gauge.
Reference: https://github.com/intel-iot-devkit/python-cv-samples/tree/master/examples/analog-gauge-reader
Hope this helps.
CODE:
import os
import cv2
import numpy
def getScriptDir():
currentFile = __file__ # May be 'my_script', or './my_script' or
realPath = os.path.realpath(currentFile) # /home/user/test/my_script.py
dirPath = os.path.dirname(realPath)
return dirPath
def getUserRealGaugeDetails():
min_angle = input('Min derece: ') #the lowest possible angle
max_angle = input('Max derece ') #highest possible angle
min_value = input('Min deger: ') #usually zero
max_value = input('Max deger: ') #maximum reading of the gauge
units = input('Birim girin: ')
return min_angle,max_angle,min_value,max_value,units
def setStaticUserRealGaugeDetails():
min_angle = 5 # input('Min angle (lowest possible angle of dial) - in degrees: ') #the lowest possible angle
max_angle = 355 # input('Max angle (highest possible angle) - in degrees: ') #highest possible angle
min_value = -20 #input('Min value: ') #usually zero
max_value = 120 #input('Max value: ') #maximum reading of the gauge
units = 'b' #input('Enter units: ')
return min_angle,max_angle,min_value,max_value,units
def getImage():
dirPath = getScriptDir()
dirPath += "/images/1.jpg"
return cv2.imread(dirPath)
def distance2Points(x1, y1, x2, y2):
#print np.sqrt((x2-x1)^2+(y2-y1)^2)
return numpy.sqrt((x2 - x1)**2 + (y2 - y1)**2)
def averageCircle(circles, b):
avg_x=0
avg_y=0
avg_r=0
for i in range(b):
#optional - average for multiple circles (can happen when a gauge is at a slight angle)
avg_x = avg_x + circles[0][i][0]
avg_y = avg_y + circles[0][i][1]
avg_r = avg_r + circles[0][i][2]
avg_x = int(avg_x/(b))
avg_y = int(avg_y/(b))
avg_r = int(avg_r/(b))
return avg_x, avg_y, avg_r
#return the center and radius of the circle
def getCircleAndCustomize(image):
height, width = image.shape[:2]
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) #convert to gray
# gray = cv2.GaussianBlur(gray, (5, 5), 0)
# gray = cv2.medianBlur(gray, 5)
# cv2.imwrite('C:/Users/okarademirci/Desktop/analog-gauge-reader/images/gauge-gray-2.jpg', gray)
#detect circles
#restricting the search from 35-48% of the possible radii gives fairly good results across different samples. Remember that
#these are pixel values which correspond to the possible radii search range.
circles = cv2.HoughCircles(gray, cv2.HOUGH_GRADIENT, 1, 20, numpy.array([]), 100, 50, int(height*0.35), int(height*0.48))
#coordinates and radius
a, b, c = circles.shape
x,y,r = averageCircle(circles, b)
return x ,y ,r
def get_current_value(img, min_angle, max_angle, min_value, max_value, x, y, r):
gray2 = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
# Set threshold and maxValue
thresh = 175
maxValue = 255
# for testing purposes, found cv2.THRESH_BINARY_INV to perform the best
# th, dst1 = cv2.threshold(gray2, thresh, maxValue, cv2.THRESH_BINARY);
# th, dst2 = cv2.threshold(gray2, thresh, maxValue, cv2.THRESH_BINARY_INV);
# th, dst3 = cv2.threshold(gray2, thresh, maxValue, cv2.THRESH_TRUNC);
# th, dst4 = cv2.threshold(gray2, thresh, maxValue, cv2.THRESH_TOZERO);
# th, dst5 = cv2.threshold(gray2, thresh, maxValue, cv2.THRESH_TOZERO_INV);
# cv2.imwrite('gauge-%s-dst1.%s' % (gauge_number, file_type), dst1)
# cv2.imwrite('gauge-%s-dst2.%s' % (gauge_number, file_type), dst2)
# cv2.imwrite('gauge-%s-dst3.%s' % (gauge_number, file_type), dst3)
# cv2.imwrite('gauge-%s-dst4.%s' % (gauge_number, file_type), dst4)
# cv2.imwrite('gauge-%s-dst5.%s' % (gauge_number, file_type), dst5)
# apply thresholding which helps for finding lines
th, dst2 = cv2.threshold(gray2, thresh, maxValue, cv2.THRESH_BINARY_INV)
# found Hough Lines generally performs better without Canny / blurring, though there were a couple exceptions where it would only work with Canny / blurring
#dst2 = cv2.medianBlur(dst2, 5)
#dst2 = cv2.Canny(dst2, 50, 150)
#dst2 = cv2.GaussianBlur(dst2, (5, 5), 0)
# for testing, show image after thresholding
dirPath = getScriptDir() + '/images/afterTreshold.jpg'
cv2.imwrite(dirPath, dst2)
# find lines
minLineLength = 10
maxLineGap = 0
lines = cv2.HoughLinesP(image=dst2, rho=3, theta=numpy.pi / 180, threshold=100,minLineLength=minLineLength, maxLineGap=0) # rho is set to 3 to detect more lines, easier to get more then filter them out later
#for testing purposes, show all found lines
# for i in range(0, len(lines)):
# for x1, y1, x2, y2 in lines[i]:
# cv2.line(img, (x1, y1), (x2, y2), (0, 255, 0), 2)
# cv2.imwrite('gauge-%s-lines-test.%s' %(gauge_number, file_type), img)
# remove all lines outside a given radius
final_line_list = []
#print "radius: %s" %r
diff1LowerBound = 0.15 #diff1LowerBound and diff1UpperBound determine how close the line should be from the center
diff1UpperBound = 0.25
diff2LowerBound = 0.5 #diff2LowerBound and diff2UpperBound determine how close the other point of the line should be to the outside of the gauge
diff2UpperBound = 1.0
for i in range(0, len(lines)):
for x1, y1, x2, y2 in lines[i]:
diff1 = distance2Points(x, y, x1, y1) # x, y is center of circle
diff2 = distance2Points(x, y, x2, y2) # x, y is center of circle
#set diff1 to be the smaller (closest to the center) of the two), makes the math easier
if (diff1 > diff2):
temp = diff1
diff1 = diff2
diff2 = temp
# check if line is within an acceptable range
if (((diff1<diff1UpperBound*r) and (diff1>diff1LowerBound*r) and (diff2<diff2UpperBound*r)) and (diff2>diff2LowerBound*r)):
line_length = distance2Points(x1, y1, x2, y2)
# add to final list
final_line_list.append([x1, y1, x2, y2])
#testing only, show all lines after filtering
# for i in range(0,len(final_line_list)):
# x1 = final_line_list[i][0]
# y1 = final_line_list[i][1]
# x2 = final_line_list[i][2]
# y2 = final_line_list[i][3]
# cv2.line(img, (x1, y1), (x2, y2), (0, 255, 0), 2)
# assumes the first line is the best one
x1 = final_line_list[0][0]
y1 = final_line_list[0][1]
x2 = final_line_list[0][2]
y2 = final_line_list[0][3]
cv2.line(img, (x1, y1), (x2, y2), (0, 255, 0), 2)
#for testing purposes, show the line overlayed on the original image
#cv2.imwrite('gauge-1-test.jpg', img)
#cv2.imwrite('C:/Users/okarademirci/Desktop/analog-gauge-reader/images/gauge-%s-lines-2.%s' % (gauge_number, file_type), img)
#find the farthest point from the center to be what is used to determine the angle
dist_pt_0 = distance2Points(x, y, x1, y1)
dist_pt_1 = distance2Points(x, y, x2, y2)
if (dist_pt_0 > dist_pt_1):
x_angle = x1 - x
y_angle = y - y1
else:
x_angle = x2 - x
y_angle = y - y2
# take the arc tan of y/x to find the angle
res = numpy.arctan(numpy.divide(float(y_angle), float(x_angle)))
#np.rad2deg(res) #coverts to degrees
# print x_angle
# print y_angle
# print res
# print np.rad2deg(res)
#these were determined by trial and error
res = numpy.rad2deg(res)
if x_angle > 0 and y_angle > 0: #in quadrant I
final_angle = 270 - res
if x_angle < 0 and y_angle > 0: #in quadrant II
final_angle = 90 - res
if x_angle < 0 and y_angle < 0: #in quadrant III
final_angle = 90 - res
if x_angle > 0 and y_angle < 0: #in quadrant IV
final_angle = 270 - res
#print final_angle
old_min = float(min_angle)
old_max = float(max_angle)
new_min = float(min_value)
new_max = float(max_value)
old_value = final_angle
old_range = (old_max - old_min)
new_range = (new_max - new_min)
new_value = (((old_value - old_min) * new_range) / old_range) + new_min
return new_value
def main():
# 1) get the image from directory.
image = getImage()
min_angle,max_angle,min_value,max_value,units = setStaticUserRealGaugeDetails()
# 2) covnert the image to gray .
# 3) find the circle in the image with customization
x,y,r = getCircleAndCustomize(image)
# 4) find the line in the circle.
# 5) find the value in the range of guage
newValue = get_current_value(image,min_angle,max_angle,min_value,max_value,x,y,r)
print(newValue)
if __name__=='__main__':
main()

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