Image editing prior to processing

Has anyone had any luck with processing images and still having Pix4D recognize the camera model and parameters associated with it? Or is there any way to manually enter this into the program for proper image calibration? I am trying to model a rotating object using snapshots of it against different images of a circular background, so I have to crop and add layers to the photos before importing them and Pix4D won’t recognize the original camera parameters. I edited the photos in GIMP, so perhaps that is where the camera information is getting lost. 

Dear Travis,

We recommend keeping the same image size (number of pixel) for all the images. As long as you do not change the EXIF tags, the camera model will still be recognized if it is in the database.

Please note that modifying the images could lead to a project that does not calibrate since it will be more difficult to match keypoints across images. It can work, but is in general not recommended.

You can edit the camera model here

Best regards,