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Color Differences In Images Collected On Different Days

MS_Comp_Review.pdf (2.1 MB)
Over the course of 3 days I created an orthomosaic of my study area using a P4 MS drone. I did not think that the weather conditions varied that much between the days but after processing the multispectral ortho I am seeing a lot of variation between the ortho of images from day 1 and day 2, day 1 and day 3, etc…

Is there anything that can be done to adjust these images, either in post or pre processing, so that the final ortho looks cleaner (for lack of better words)? Or would the best course of action be to re-fly the study area?

Hi,
Could you please send us the following?

▸ The quality report (.pdf format): …\project_name\1_initial\report\project_name_report.pdf
▸ The project log file (text file): …\project_name\project_name.log

Best,

FinalMerge_report.pdf (1.4 MB)
FinalMerge.log (98.1 KB)

Aloha,
Above are the requested files.

Hello,

I see that you tried to merge the different projects. May I ask if you followed the steps suggested in this article How to merge projects – Support ?

Best,

Yes, I have followed those steps.

Hi,

Fly all the images with the same weather and light condition could certainly help solve the issue.

However, there are 3 suggestions (A, B, and C) you can try without re-taking the images:

A: Third party application
A user suggested using a third-party application in order to modify the images and balance them in order to make them look more similar:

However, you should pay attention not to remove the EXIF information from the images. In general, we do not suggest modifying the original images and use modified images as input for PIX4Dmapper.

B: Radiometric Corrections in Processing Options of step 3
In the processing options in Step 3. DSM, Orthomosaic and Index in the Index Calculator tab Please select Radiometric corrections > Correction type > (here change the correction type)
Please verify in our Pix4D Documentation about Radiometric corrections in order to find out the best correction for your data. For more information: Camera radiometric correction specifications.

C: Disable Color Balancing
Also, if the previous suggestion did not work, you could try to disable the color balancing in the mosaic generation. According to our experience, this can help in some cases.
Unfortunately, at this moment, we are not able to make this change via the user interface. What you can do is to:

  1. Process the three steps.
  2. Open .p4d file. (located in …\project_name.p4d). Please use a text editor to open the .p4d file
  3. Look for the <mosaicGainc> tag.
  4. Replace true with false.
  5. Start again with the 3rd Step.

Let me know if any of this suggestion is helpful.

Cheers

I have gone through and tried each of these suggestions to no avail. I appreciate this response and will surely use these methods to troubleshoot my issues next time around! Thank you so much Daniele, I greatly appreciate your help!

Thank you for trying the suggestions provided. Unfortunately, it seems that the differences between the different projects were too important.
Acquiring images with the same weather and light condition could certainly help solve the issue in the future.