This article explains the procedure on how to verify that the Image Quality is sufficient for PIX4Dmapper. 

To verify that the image quality is sufficient, visualize the images and check that:

1. The images are not blurry. If the images are blurry, check the camera settings (Step 1. Before Starting a Project > 2. Configuring the Camera Settings) and acquire a new dataset.
2. The images have enough image content. Images do not have enough content if the scene contains, for example, water, mirror, or glass surfaces. In such cases, capturing a dataset by flying higher might help.
3. The images have sufficient resolution. Small images (e.g. 640x480 pixels) have little content.

• If possible acquire images of a higher resolution.
• If not, set the Image Scale for feature extraction to 2 (Double image size) in the Processing Options (Menu Process > Processing Options... > 1. Initial Processing > General).