# How to efficiently concat multiple images and overlap the duplicates part of the images **URL:** \ **Category:** Python\ **Tags:** imgproc\ **Created:** [August 20, 2023, 11:51am UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299 "2023-08-20T11:51:22Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Vikas\_Gupta](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/vikas_gupta/32/8563_2.png) [@Vikas\_Gupta](https://forum.opencv.org/u/Vikas_Gupta)\ **Post date:** [August 20, 2023, 11:51am UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/1 "2023-08-20T11:51:22Z")
Hey team, I have around 40 images and need to concat them into 1 and in order. the possible aspect ratio can be 4x5 or 5x4 based on how many images will be in rows and how many in columns. I tried using hconcat and vconcat but that needs some overlapping on the image edges. I also tried image stitching but 2 images can be similar but not of same object so stitching is assuming them to be same and not working properly. I am assuming I need some solution where I am applying stitching after the concat just to remove duplicates. can anyone help me to how can I achieve it? ---
**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\ **Post date:** [August 20, 2023, 12:28pm UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/2 "2023-08-20T12:28:26Z")
> [@Vikas\_Gupta](#): > > I tried using hconcat and vconcat but that needs some overlapping on the image edges. why ? please explain > [@Vikas\_Gupta](#): > > I also tried image stitching well, _that_ needs some overlap (and as you found out, from the _same_ image) > [@Vikas\_Gupta](#): > > where I am applying stitching after the concat just to remove duplicates. you probably want to filter your _part_ images before for duplicates (using phash or similar) . stitching cannot do this ---
**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\ **Post date:** [August 20, 2023, 1:08pm UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/3 "2023-08-20T13:08:18Z")
show your data please ---
**Author:** ![Vikas\_Gupta](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/vikas_gupta/32/8563_2.png) [@Vikas\_Gupta](https://forum.opencv.org/u/Vikas_Gupta)\ **Post date:** [August 20, 2023, 2:27pm UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/4 "2023-08-20T14:27:49Z")
[https://www.sendgb.com/upload/?utm\_source=2ym6pvqa7lY](https://www.sendgb.com/upload/?utm_source=2ym6pvqa7lY) there are 2 sample data on it. This is basically what I wanted to try “”" My product is a roll. I have a camera that takes photos of my product. I take about 40 or 50 photos to complete the overview. i need to merge them firstly and compare with the tiff file of my roll. and detect some defects on it i need to see differences like in a diff but the most important thing, i don’t have 2 photos to compare i have 1 TIFF file and 40-50 or 60 small photos that will be same as tiff file when connected “”" In the sample there are 2 folders “230816\_14/230816\_14” and “230816\_13/230816\_13” Where each folder contains 20 pictures There are tiff files for both of these samples “23.08.16\_13.jpg” and “23.08.16\_14.tif” File extension doesn’t matter here. Now I am confused on how to proceed with it. ---
**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\ **Post date:** [August 20, 2023, 3:17pm UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/5 "2023-08-20T15:17:40Z")
your “sendgb” link doesn’t actually link to anything. ---
**Author:** ![Vikas\_Gupta](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/vikas_gupta/32/8563_2.png) [@Vikas\_Gupta](https://forum.opencv.org/u/Vikas_Gupta)\ **Post date:** [August 20, 2023, 3:20pm UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/6 "2023-08-20T15:20:14Z")
> **[Desktop.zip](https://drive.google.com/file/d/14HZ1U0XwPeaDAuShQzO2X1JiujgMwHuy/view?usp=sharing)** > > Google Drive file. sorry for the issue with the link, You may try this. ---
**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\ **Post date:** [August 21, 2023, 5:44am UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/7 "2023-08-21T05:44:16Z")
> [@Vikas\_Gupta](#): > > compare with the tiff file of my roll. > > and detect some defects on it is _that_ the actual job ? **defect detection** on rolls ? ---
**Author:** ![Vikas\_Gupta](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/vikas_gupta/32/8563_2.png) [@Vikas\_Gupta](https://forum.opencv.org/u/Vikas_Gupta)\ **Post date:** [August 21, 2023, 9:01am UTC](https://forum.opencv.org/t/how-to-efficiently-concat-multiple-images-and-overlap-the-duplicates-part-of-the-images/14299/8 "2023-08-21T09:01:46Z")
Yes, This is the actual job.