Develop Reference

Python Tesseract not recognising number in my image

I've got this picture (preprocessed image) from which I want to extract the numeric values of each line. I'm using pytesseract but it doesnt show any results for this image.
I've tried several config options from other questions like "--psm 13 --oem 3" or whitelisting numbers but nothing yields results.
As a result I usually get just one or two characters or ~5 dots/dashes but nothing even remotly resembling the size of my input.
I hope someone can help me cheers in advance for your time.
pytesseract version: 0.3.8
tesseract version: 5.0.0-alpha.20210506

You must think to use --psm 4, it's more appropriate for your image. I also recommend to rethink about the image pre-process. Tesseract is not perfect and it requires good image as input to work well.
import cv2 as cv
import pytesseract as tsr
img = cv.imread('41DAx.jpg')
img = cv.cvtColor(img, cv.COLOR_BGR2RGB)
config = '--psm 4 -c tessedit_char_whitelist=0123456789,'
text = tsr.image_to_string(img, config=config)
print(text)
The above code was not able to well detect all digts in the image, but almost of them. Maybe with a bit of image pre-processing, you can reach your objective.

Why can't Tesseract identify text that's contained in a larger box?

I am trying to extract some really obvious text from an image that's contained in a wider box:
However, Tesseract is not successful extracting the text from it. If I remove the box in the image, it works just fine:
Note, that when I change the font to something more common (e.g. Arial), it will work fine for both images. But, I do need to make it work with the current font (Impact).
Any help on how to get that to work would be hugely appreciated!
Below is my current code:
import cv2
import pytesseract
pytesseract.pytesseract.tesseract_cmd = r'C:\\Program Files\\Tesseract-OCR\\tesseract.exe'
img = cv2.imread('without_box.png') #https://i.stack.imgur.com/vrJvd.png
img_text = pytesseract.image_to_string(img)
print('without_box : ', img_text) #returns "without_box : TEXT"
img = cv2.imread('with_box.png') #https://i.stack.imgur.com/xNEdR.png
img_text = pytesseract.image_to_string(img)
print('with_box : ', img_text) #returns "with_box : "

For the presented kind of images1, you could automatically crop the white part which holds the text, and run pytesseract:
import cv2
import pytesseract
def crop_and_detect(image):
thr = cv2.threshold(image, 128, 255, cv2.THRESH_BINARY)[1]
x, y, w, h = cv2.boundingRect(thr)
return pytesseract.image_to_string(image[y:y+h, x:x+w])
for img_file in ['vrJvd.png', 'xNEdR.png']:
img = cv2.imread(img_file, cv2.IMREAD_GRAYSCALE)
print(img_file, crop_and_detect(img).replace('\f', ''))
# vrJvd.png TEXT
#
# xNEdR.png TEXT
#
----------------------------------------
System information
----------------------------------------
Platform: Windows-10-10.0.19041-SP0
Python: 3.9.1
PyCharm: 2021.1.2
OpenCV: 4.5.2
pytesseract: 5.0.0-alpha.20201127
----------------------------------------
1 If you have an image processing related question, provide a representative set of possible input images. Otherwise, you might get a proper solution for the one or two input images you provided, but while testing that solution on your actual data set, you find out "it doesn't work", and possibly post (a lot of) follow-up questions, which could've prevented in the first place.

Can't extract text from an image with python OCR pytesseract

I'm trying to extract texts from some images. It worked for hundreds of other images but in some cases it doesn't find any texts. In order to optimize the images for extraction phase, all images are converted to black and white. All of their backgrounds are white and others are black such as icons, texts etc.
For example it worked for below image and succesfully found 'Sleep Timer' text in the image. I'm not sure if it's relevant but size of the below image with 'Sleep Timer' text is 320 × 351
But for the below image it doesn't find any text at all. Image size for this one is 161 × 320.
Since I couldn't find the reason, I tried to resize the image but it didn't work.
Here is my code:
from pytesseract import Output
import pytesseract
import cv2
image = cv2.imread('imagePath')
rgb = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
results = pytesseract.image_to_data(rgb, output_type=Output.DICT)
for i in range(0, len(results["text"])):
text = results["text"][i]
conf = int(results["conf"][i])
print("Confidence: {}".format(conf))
print("Text: {}".format(text))
print("")

It is working for me I tested:
import pytesseract
print(pytesseract.image_to_string('../images/grmgrm.jfif'))
results = pytesseract.image_to_data('../images/grmgrm.jfif', output_type=pytesseract.Output.DICT)
print(results)
Are you getting an error? Show us the error you are getting.

Why can't tesseract extract text that has a black background?

I have attached a very simple text image that I want text from. It is white with a black background. To the naked eye it seems absolutely legible but apparently to tesseract it is a rubbish. I have tried changing the oem and psm parameters but nothing seems to work. Please note that this works for other images but for this one.
Please try running it on your machine and see if it works. Or else I might have to change my ocr engine altogether.
Note: It was working earlier until I tried to add black pixels around the image to help the extraction process. Also I don't think that tesseract was trained on black text on a white background. It should be able to do this too. Also if this was true why does it work for other text images that have the same format as this one
Edit: Miraculously I tried running the script again and this time it was able to extract Chand properly but failed in the below mentioned case. Also please look at the parameters I have used. I have read the documentation and I feel this would be the right choice. I have added the image for your reference. It is not about just this image. Why is tesseract failing for such simple use cases?

To find the desired result, you need to know the followings:
Page-segmentation-modes
Suggested Image processing methods
The input images are boldly written, we need to shrink the bold font and then assume the output as a single uniform block of text.
To shrink the images we could use erosion
Result will be:
Erode
Result
CHAND
BAKLIWAL
Code:
# Load the library
import cv2
import pytesseract
# Initialize the list
img_lst = ["lKpdZ.png", "ZbDao.png"]
# For each image name in the list
for name in img_lst:
# Load the image
img = cv2.imread(name)
# Convert to gry-scale
gry = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
# Erode the image
erd = cv2.erode(gry, None, iterations=2)
# OCR with assuming the image as a single uniform block of text
txt = pytesseract.image_to_string(erd, config="--psm 6")
print(txt)

Detecting Bangla character using pytesseract

I am trying to detect bangla character from image using python, so i decided to use pytesseract. For this purpose i have used below code:
import pytesseract
from PIL import Image, ImageEnhance, ImageFilter
im = Image.open("input.png") # the second one
im = im.filter(ImageFilter.MedianFilter())
enhancer = ImageEnhance.Contrast(im)
im = enhancer.enhance(2)
im = im.convert('1')
im.save('temp2.png')
pytesseract.pytesseract.tesseract_cmd = 'C:/Program Files (x86)/Tesseract-OCR/tesseract'
text = pytesseract.image_to_string(Image.open('temp2.png'),lang="ben")
print text
The problem is that if i gave a image of english character is detects. But when i am writing lang="ben" and detecting from image of bengali characters my code is running for endless time or like forever.
P.S: I have downloaded bengali language train data to tessdata folder and i am trying to run it in PyCharm.
Can anyone help me to solve this problem?
sample of input.png

I added Bangla(india) language to Windows. Downloaded ben.traineddata to TESSDATA_PREFIX which equals to C:\Program Files\Tesseract 4.0.0\tessdata in my PC. Then run,
> tesseract -l ben bangla.jpg bangla_out
in command prompt and got the result below in 2 seconds. The result looks fine even I don't understand the language.
Have you tried to run tesseract in command prompt to verify if it works for -l ben?
EDIT:
Used Spyder, similar to PyCharm, which comes with Anaconda to test
it. Modified your code to call Tesseract as below.
pytesseract.pytesseract.tesseract_cmd = "C:/Program Files/Tesseract 4.0.0/tesseract.exe"
Test Code in Spyder:
import pytesseract
from PIL import Image, ImageEnhance, ImageFilter
import os
im = Image.open("bangla.jpg") # the second one
im = im.filter(ImageFilter.MedianFilter())
enhancer = ImageEnhance.Contrast(im)
im = enhancer.enhance(2)
im = im.convert('1')
im.save("bangla_pp.jpg")
pytesseract.pytesseract.tesseract_cmd = "C:/Program Files/Tesseract 4.0.0/tesseract.exe"
text = pytesseract.image_to_string(Image.open("bangla_pp.jpg"),lang="ben")
print text
It works and produced result below on the processed image. Apparently, the OCR result of the processed image is not as good as the original one.
Result from the processed bangla_pp.jpg:
প্রত্যাবর্তনকারীরা
তাঁদের দেশে গিয়ে
-~~-<~~~~--
প্রত্যাবর্তন-পরবর্তী
আর্থিক সহায়তা
= পাবেন তার
Result from original image, directly feed to Tesseract.
Code:
from PIL import Image
import pytesseract as tess
print tess.image_to_string(Image.open('bangla.jpg'), lang='ben')
Output:
প্রত্যাবর্তনকারীরা
তাঁদের দেশে গিয়ে
প্রত্যাবর্তন-পরবর্তী
আর্থিক সহায়তা
পাবেন তার

I have installed some fonts in windows from here
https://www.omicronlab.com/bangla-fonts.html
After that, it worked perfectly fine for me in Pycharm.