- Standard georeferencing with meter level of accuracy using the integrated (phone) GNSS/GPS sensor.
- RTK georeferencing with a supported RTK Device for centimeter-level accuracy. For more information: How to use PIX4Dcatch a supported RTK device.
IN THIS ARTICLE
Information: There are different ways to georeference the images:
Capture a project
Before you start capturing, it is recommended to plan a capture route for best results. Determine an optimal direction to take. Depending on the subject matter and size, circular and/or linear capture paths can be followed. For larger subjects, the use of multiple parallel paths (horizontal or vertical) can be considered with adequate overlap between paths.
- Tap the record button and slowly move the device to start capturing. The app will automatically start capturing images based on the selected settings.
- If necessary, tap the pause button to pause the recording. Tap the record button to start recording again.
Important: Use the pause button only when necessary, and return close to where the pause was initiated.
- iOS and Android users who have LiDAR or ToF sensors in their devices can use the Live Preview feature to gain insight into what is being captured.
- After the capture is complete, tap to save the captured project. The cancel button can be used to abort a project while capturing.
- After tapping the button, a capture report will be displayed for reviewing the overall project quality. The following information is displayed:
- Project Name.
- Images - Number of images taken for the capture.
- Tap to center the project.
- Tap to access:
- Toggle the camera positions visibility.
- Toggle Sparse point cloud. Available for devices with a TOF and/or LiDAR sensor. Tie points will be displayed for devices without these sensors.
- Close the menu.
- After tapping Save, the project is created and stored on the device.
Tips:
- Fill the image frame with the content you wish to reconstruct.
- Employ a slight downward tilt.
- Point the camera to capture near and far.
- Avoid moving objects including the shadow of the operator.
- Capture rich textures in good lighting.
- Move and turn Slowly.
- Do not change the orientation of the camera while standing still. e.g. turn in place.
- Avoid any sudden perspective changes / rapid or waving motions.
- Try to maintain a consistent distance between the camera and what it captures.
- Plan for smooth transitions around corners.
- It is better to raise or lower the camera height when trying to capture further detail in higher or lower regions than it is to point the camera up/down from the same height.
- Plan.
- Identify areas that may have limited visibility due to scene geometry.
- Plan the image collection with consideration to lighting.
- Consider potential locations for manual tie points and ground control points. Distribute accordingly.
- In difficult terrain, a practice run can help.
- Try to avoid.
- Low light scenes, if you need to scan a scene with poor lighting try to move slowly or use artificial light avoiding shadows.
- Pointing the camera in the exact direction of travel/Dead ahead.
- Face the camera at an angle from the direction of travel.
- Try not to travel back exactly over the same path.
- Change the elevation and plath slightly, whenever necessary to double over a previously captured region.
- Ensure stable internet.
- Use WiFi only if the scene has full coverage and the connection is stable.
- Turning WiFi off is a good idea, as WiFi may shadow mobile data (4G) connection, even if it has a weak signal. Projects with mixed WiFi and mobile connection may fail.
With the project saved, it can be uploaded for processing or the device is ready to start a new project.
Tip: To use automatic Tag Detection during capturing, please import the Point Collection before capturing. For more information: How to use automatic Tag Detection and manual GCP marking - PIX4Dcatch RTK
Processing a PIX4Dcatch project for more information on how to process.
How to export PIX4Dcatch projects (iOS/Android) for more information on how to export your project to save or process locally.