Develop Reference

Can we read Following image of captcha if yes then how to do that with pytesseract

I am trying to read images with pytesseract but on one website it works and on other site it don't work.
The following image is readable by my current code.
The following image is unable to be read by my current code.
from PIL import Image
from pytesseract import pytesseract
#Define path to tessaract.exe
path_to_tesseract = '/usr/bin/tesseract'
#Define path to image
path_to_image = './captcha.png'
#Point tessaract_cmd to tessaract.exe
pytesseract.tesseract_cmd = path_to_tesseract
#Open image with PIL
img = Image.open(path_to_image)
#Extract text from image
text = pytesseract.image_to_string(img)
print(text)

openCV and Tesseract text detection returning no output

im using openCV and Tesseract to make a text recognition software but it is returning no output
this is my code:
from PIL import Image
from pytesseract import pytesseract
import time
import cv2 as cv
camera_port = 0
camera = cv.VideoCapture(camera_port, cv.CAP_DSHOW)
time.sleep(0.1) # If you don't wait, the image will be dark
return_value, image = camera.read()
cv.imwrite("pic.png", image)
del(camera) # so that others can use the camera as soon as possible
image_path = "pic.png"
path_to_tesseract = r"C:\Program Files\Tesseract-OCR\tesseract.exe"
img = Image.open(image_path)
pytesseract.tesseract_cmd = path_to_tesseract
text = pytesseract.image_to_string(img)
print(text)
and it took this
photo
but it gave no output or error, any suggestions?

As you are using import as from pytesseract import pytesseract, image_to_string function is not be available in the class you imported, It will be present in pytesseract module itself.
Try this
import pytesseract
pytesseract.pytesseract.tesseract_cmd = r"C:\Program Files\Tesseract-OCR\tesseract.exe"
text = pytesseract.image_to_string(img, lang='eng')

Image always renders as a gray box

When I load a set of image files into a list and try to display one, it always renders as a gray box.The images are not gray boxes. The size of the image window displayed by openCV varies with the size of the actual image on file.
import cv2
import glob
import random
def loadImages(path):
imdir = path
ext = ['png', 'jpg', 'gif'] # Add image formats here
files = []
[files.extend(glob.glob(imdir + '*.' + e)) for e in ext]
#print("files", files)
images = [cv2.imread(file) for file in files]
return images
images = loadImages("classPhotos/")
print(str(len(images)), "images loaded")
#print(images)
cv2.imshow("image", random.choice(images))
tmp = input()

Add this 2 lines after cv2.imshow("image", random.choice(images)) to make it work properly.
cv2.waitKey(0)
cv2.destroyAllWindows()
cv2.imshow shows the image instantly and then doesn't show it.
cv2.waitKey waits for a specific time/ keeps showing the image.
putting 0 as an argument makes it wait infinitely unless a key is pressed.
cv2.destroyAllWindows() helps close the window otherwise it gets stuck.

How to extract numbers from a complex captcha

I am trying to resolve captcha for the following image
!https://ibb.co/35X723J
I have tried using tessaract
data = br.open(captchaurl).read()
b = bytearray(data)
save = open(filename, 'wb')
save.write(data)
save.close()
ctext= pytesseract.image_to_string(Image.open(filename))

Here is a workaround. You need to clear a bit the image but you wont get a perfect result. Try the following:
try:
from PIL import Image
except ImportError:
import Image
import pytesseract
import cv2
file = 'sample.jpg'
img = cv2.imread(file, cv2.IMREAD_GRAYSCALE)
img = cv2.resize(img, None, fx=10, fy=10, interpolation=cv2.INTER_LINEAR)
img = cv2.medianBlur(img, 9)
th, img = cv2.threshold(img, 185, 255, cv2.THRESH_BINARY)
kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (4,8))
img = cv2.morphologyEx(img, cv2.MORPH_CLOSE, kernel)
cv2.imwrite("sample2.jpg", img)
file = 'sample2.jpg'
text = pytesseract.image_to_string(file)
print(''.join(x for x in text if x.isdigit()))

Option 1:
I think using Pytesseract should solve the issue. I tried out your code and it gave me the following result when i gave in the exact cropped captcha image as input into pytesseract:
Input Image:
Output:
print(ctext)
'436359 oS'
I suggest you don't give the full page url as input into pytesseract. Instead give the exact image url as "https://i.ibb.co/RGn9fF5/Jpeg-Image-CS2.jpg" which will take in only the image.
And regarding the extra 'oS' characters in the output, you can do a string manipulation to chop off the characters other than numbers in the output.
re.sub("[^0-9]", "", ctext)
Option 2:
You can also use google's OCR to accomplish this which gives you the exact result without errors. Though I have shown you the web interface of it, google has nice python libraries through which you can accomplish this using python itself. Looks like this:

opencv python face detection from url images

I have no problem getting the opencv face detection using haar feature based cascades working on saved images:
from PIL import Image
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')
img = cv2.imread('pic.png')
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)
but I can't figure out how to open a url image and pass it into face_cascade. I've been playing around with cStringIO, but I don't know what to do with it...
import cv2.cv as cv
import urllib, cStringIO
img = 'http://scontent-b.cdninstagram.com/hphotos-prn/t51.2885-15/10424498_582114441904402_1105042543_n.png'
file = cStringIO.StringIO(urllib.urlopen(img).read())
source = Image.open(file).convert("RGB")
bitmap = cv.CreateImageHeader(source.size, cv.IPL_DEPTH_8U, 3)
cv.SetData(bitmap, source.tostring())
cv.CvtColor(bitmap, bitmap, cv.CV_RGB2BGR)
is it possible to work with a numpy array instead?
source2 = Image.open(file)
imarr=numpy.array(source2,dtype=numpy.uint8)
I'm a beginner, so I apologize for the poor explanation.
thanks a lot in advance!!

In your first example you are using OpenCV2.imread to read your image in the second you are presumably using PIL.Image then trying to convert.
Why not simply save the file to a temp directory and then use OpenCV2.imread again?

Or in another way you can use VideoCapture() class to open url image.
See the C++ code below,
VideoCapture cap;
if(!cap.open("http://docs.opencv.org/trunk/_downloads/opencv-logo.png")){
cout<<"Cannot open image"<<endl;
return -1;
}
Mat src;
cap>>src;
imshow("src",src);
waitKey();