question: this method speed up the proccess with GCPs is ok?


using the Method A (default) from the online help in this website:

The weak point of this process is the human intervention after finishing step 1 and looking for the coincidence of the GCPs, to then optimize and do steps 2 and 3.

If I modify the configuration of step 1 to speed it up and set it to 1/8 or 1/4 image size and once step 1 is finished, I load the CGPs and look for matches in the raycloud. Once this step is done I set step 1 back to full or original image size and do the full step 1 again without reoptimizing (actually I can leave steps 1, 2 and 3 consecutively) overnight…
Is this correct? Or do I necessarily have to do step 1 in the default quality, load and match the GCPS, re-optimize and finish steps 2 and 3.

My way of working reduces the time at the beginning of the task, since in a few minutes the GCPS are loaded and matched with the photos and you can leave it re-doing the whole process without assistance.

Hi Lui,

Thank you for your explanation of your project.

If you process step 1 again after running a step 1 and marking GCPs, the result of the first step 1 will be overwritten. It is best to marked GCPs > run Reoptimization > run step 2 and 3 when following Method A.

There is also Method C. Method C works for any case , no matter the coordinate system of the images or GCPs, but it requires more time to mark the GCPs on the images. The advantage of this method is that after importing the images and the GCPs, the processing can be done without any intervention by the user. Perhaps, this could compensate for what you mentioned about Method A requiring human intervention after step 1.

May I ask to confirm if your goal is to reduce some processing time?

If that is the case, each step utilizes the computer hardware differently. Using and adjusting the settings of the appropriate hardware can help to reduce the processing time. For example, step 1 heavily relies on the GPU. You can set the graphic setting for PIX4Dmapper to high performance by going to Windows > Settings > Display > Graphics. I am using Windows 11. It could be slightly different if you are using a different OS. Feel free to have a look at this article.

Hardware components usage when processing with PIX4Dmapper

You can also reduce the processing time by adjusting the processing options as you may have already experienced by changing the image scale for step 1. There are other ways you can adjust in step 2 and 3 for which you can follow this video here: How to reduce project processing time - Pix4Dmapper Video Tutorial 16

I hope this is helpful. Feel free to share if this information helps. We always welcome any feedback and to learn from you all.