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Color variance problem in Orthophotos

Recently I started getting those purple-ish areas in Orthophotos. Images are taken with Sony A5100, 16mm lens, Daylight white balance, Manual exposure.

Never had this with older versions.

Anyone noticed that? Any suggestions?

Hey Rami,

By default, in Pix4Dmapper the orthomosaic is color balanced, but you could try to deactivate the Color balancing option. 

If you edit the .p4d file and change the : <mosaicGainc>true</mosaicGainc> to false then the orthomosaic will not be color balanced. 

Be careful since you need modify the .p4d file and erroneous changes might prevent you from opening your project! 

Best Regards, 

 

Once <mosaicGainc>true</mosaicGainc> is set to False - what steps to execute so that the orthomosaic is saved with true colors?

May please advise.

Thanks!

Achyut

 

 

Hi Achyut,

Once the .p4d file is edited, you will just have to re-process step 3.
Uncheck the boxes corresponding to steps 1. and 2. (only keep 3.) in the processing bar and click Start.

Regards,

Hi,

We would like to inform you that this issue was fixed with version 3.3.24 and we do not expect issues with the colour balancing algorithm implemented in the software. This reduces greatly purple artifacts on the edges of the orthomosaics.

More here: Pix4D Desktop technical release notes - Version 3.3

Best,

Good morning

I recently started to use Rededge-M camera to capture aerial data. As I’m using a multispectral camera I can’t obtain directly a orthomosaic with all bands stacked using Ag.multispectral template (to stack the bands I have an external software). But once I obtain the final orthomosaic the purple-ish areas appears.

 

As is not possible colour balancing the image before processing I’m not really sure what the solution can be. 

I attach here couple of images (picture 1 full mosaic from study area, picture 3 zoomed in area and picture 2 google maps from study area).

Hi,

This issue seems to be related to composite image creation. As you mentioned, in our software, we do not generate RGB composite but only the single page tiff files for each sensor. From our side please note that we do not recommend to work with the orthomosaics when one is processing multispectral imagery but rather with the reflectance maps. And the is because when generating the orthomosaic color balancing is applied while for reflectance not. 

This link might be helpful: https://support.micasense.comhttps://support.pix4d.com/hc/en-us/articles/216541468-How-do-I-display-my-MicaSense-Multi-layer-GeoTiff-in-ArcMap-