Convert image with correct DPI for tesseract OCR purpose

convert_dpi.py

from subprocess import Popen,PIPE, check_output
import os, sys
import tempfile
import uuid
import cv2
import pytesseract as pt
from PIL import Image

def convert_dpi(input_image):
    path = tempfile.gettempdir()
    filename = str(uuid.uuid4())[:8] + ".jpg"
    filename_out = str(uuid.uuid4())[:8] + "_out.jpg"
    image_path = os.path.join(path, filename)
    image_path_out = os.path.join(path, filename_out)
    cv2.imwrite(image_path, input_image)
    
    proc_identify = check_output(['identify', '-format', "dpi:%y", image_path], stderr=PIPE)
    dpi = str(proc_identify).replace('dpi:','')
    print("image identify finish, DPI: "+dpi)
    proc_convert = Popen(['convert', '-units', 'PixelsPerInch', image_path, '-density', dpi, image_path_out])
    out = proc_convert.communicate()
    p_status = proc_convert.wait()
    print("image convert finished: ", out, p_status, image_path_out)
    return image_path_out


imagepath = '.......'
img = cv2.imread(imagepath)
print("first attempt: ", pt.image_to_string(img))
converted_img = convert_dpi(img)
print("second attempt: ", pt.image_to_string(cv2.imread(converted_img)))
print("thrid attempt: ", pt.image_to_string(converted_img))
print("fourth attempt: ", pt.image_to_string(Image.open(converted_img)))

Tesseract requires correct DPI info in image's meta data to work in best shape.
This may helpful for images with incorrect DPI info.

1. Get DPI info using imageMagick
2. Using Imagemagick to convert image with correct unit(inches)
3. Run pytesseract to test with input types of: 1. new image path, 2. numpy array, 3. PIL image
   The tests show that using direct image path and PIL image to run pytesseract give correct results.
   (don't forget to delete temp files)

I am getting this error "[Errno 2] No such file or directory: 'identify".