Quality of Image capture from openCV

[a.jin820206]

Hey guys!
I'm trying to capture images from my Tello drone with python using OpenCV
However, I notice that the image quality from programming is not as good as the image from the Tello app(controlled by iPhone8).
I've tried cv2.resize() method and it seems like this only changes the dimension of the image, not quality.

or should I change other parameters? like framerate, fps.....etc

If anyone knows how to improve this plz kindly let me know! Thank you!
Here is my simple code:


from djitellopy import tello
from time import sleep
import cv2
import time

global img

me = tello.Tello()
me.connect()
print(me.get_battery())

me.takeoff()


me.streamon()
img = me.get_frame_read().frame
img = me.rescale_frame()
img = cv2.resize(img, (1280, 720))
cv2.imwrite(f'Resources/Images/{time.time()}.jpg', img)
me.streamoff()

me.land()



Thank you!

 

[Hacky]

...However, I notice that the image quality from programming is not as good as the image from the Tello app(controlled by iPhone8).

Do you compare with the video stream or with still images ("photo", 5 MP) taken with the app?

 

[a.jin820206]

Yes, I did compare both. The photo quality I got from the video stream is pretty low, even tho I changed the Tello resolution to “720p”.


This is the information of the photo taken from Tello frame
Dimension: 2592 * 1936 (I did the resize method)
Horizontal Resolution: 96 dpi
Vertical Resolution: 96 dpi
Bit depth: 24


However, the photo taken by the Tello app (iphone8)has a better image quality.
info:
Dimension: 2592 * 1936
Horizontal Resolution: 96 dpi
Vertical Resolution: 96 dpi
Bit depth: 24


I'm guessing it's because the app simultaneously uses iPhone camera, that's why.

 

[Hacky]

Yes, I did compare both. The photo quality I got from the video stream is pretty low, even tho I changed the Tello resolution to “720p”.

This is the information of the photo taken from Tello frame
Dimension: 2592 * 1936 (I did the resize method)

So you wonder why a frame taken from a 720p video stream and resized afterwards to 2592x1936 looks worse than a photo taken originally at that resolution?

I'm guessing it's because the app simultaneously uses iPhone camera, that's why.

If the app would use the iPhone camera. you would see a picture from a totally differen perspective.