OpenCV3 Tutorials 9: Comparing Images and Displaying Difference

In this tutorial we explore how to compare two images and display the difference. We will be using opencv and numpy libraries.

This video demonstrates how to use opencv 3 and python 2.7 to detect faces in a stream of frames. be it a webcam/camera stream or a video file.

This video is part of the series OpenCV and Python. For a better understanding feel free to visit other videos.

Twitter: @ibrahimokdad

[HeySushil]

Thanks its helping and very easy way to find the difference.

[harisha.g]

Your tutorial made my day!!! I had a big problem to solve and u made it crystal clear!!! thank you very much man :) cheers !!

[utkarshaattarde]

Hiii... Good video!!!
I have a question... How I can see the image and show that difference in color

[Cralis]

Is there a way to handle issues like .. the brightness drops a bit. Would the whole image be different? Or can OpenCV cope with global changes like brightness (a cloud comes over and my subject seems darker)

[vincentramos]

Thanks for the video. Is it possible to compare all the images between two files and print out all of the obtained results?

[ibmgrx]

hi, do you have a template matching tutorial for realtime camera? thanks in advance

[abdulrauf-wjrw]

can you tell me how can i get the real-time image difference between two images 1st image is saved in a folder and by using cv2 i will access that image and second i will capture live using webcam

[Theleaderacademy]

Hy dear
i have this error. kindly help me please
difference = cv2.subtract(image1, image2)
cv2.error: OpenCV(4.1.0) error: (-209:Sizes of input arguments do not match) The operation is neither 'array op array' (where arrays have the same size and the same number of channels), nor 'array op scalar', nor 'scalar op array' in function 'cv::arithm_op'

[gjhouse]

Hi, thanks for the video, it was really helpful, however, If I may ask, how can I calculate the difference? for example how much similar are two given images, to what degree? Thanks !!

[hussainmerchant]

I want to compare two cattle's and want to explore the difference between muzzles. Two images may be the same but shade, colour light effect may be different. Can you help!

[satishsamineni]

I need a help in to find out the differences between two images. Problem here is write the differences on Targetted image with red color . Is there any possiblity we can do with Open CV. It will be really helpful

[vovadenys]

doesn't jpg compress the image every time that lead to missing some pixels?

[kumarpavan]

HI....I would like to find whether particular symbol or logo is in difference images ...so could you make video on it please...

[otmanechiboub]

Thank you very much for this tutos,
I have a question please? is the code that you use can compare two identical images whos had different orientations and different constrast level??
(i am sorry for my english expression )

[deepaksingh]

Very Helpful man. Thanks.

But is there a way to find out the same for video .
for example lets say i want to find out if all the frames are in video are still and same ?

[bikashchoudhury]

using python 3.5 with comparision it shows the error as ' cv2 error: 'cv2.cv2' has no attribute as 'face' '.??? what will i do....pls help me

[dawaj]

sir i do it but i have error
Diff=cv2.subtract(img1, img2)

error: error: (-209) The operation is neither 'array op array' (where arrays have the same size and the same number of channels), nor 'array op scalar', nor 'scalar op array' in function cv::arithm_op

[jenimerlin]

Can i compares text from images and find the differences

[sindhureddy]

Great explanation !!. i have a scenario. I have 2 images, image 1 and image 2 and both are different in a way that there exists a line in image 1 and not in image 2. I wanted to display result as : image 1 with the line highlighted by a bounding box or in any way. can you pls help me with inputs ?

[roxby]

thanks for the great video!!! it was realy helpfull! is there a way to get the position where the image has changed? like the
coordinate of the black dot on the ice cream image?