Accelerate GCP workflow with Tag Detection in PIX4Dcatch

In the dynamic world of photogrammetry and 3D mapping, efficiency and accuracy are paramount. Recognizing this, Pix4D has made a groundbreaking advancement with the introduction of the Tag Detection feature in PIX4Dcatch. Our goal was clear: to streamline the workflow with Ground Control Points (GCPs) and elevate the entire scanning process to new heights of precision and ease.

Traditionally, the use of GCPs, while essential to improve accuracy, came with its own set of challenges. Users, whether working with GNSS rover or without, expressed a strong need for a more integrated GCP experience. Previously, the integration of GCPs into your workflow involved a manual, somewhat cumbersome process. After capturing your scene, the next step was to painstakingly mark each GCP in the captured images – a task that could be both time-consuming and, at times, frustrating, especially when working on an iPhone.

What is Tag Detection?

Welcome Tag Detection – a feature meticulously designed to transform this scenario. With Tag Detection, the moment you capture your scene using PIX4Dcatch, a seamless and automated process kicks into gear. The feature intelligently identifies the GCP tags present on the ground and links them to the correct, pre-georeferenced GCPs in your point collection. This integration happens in real-time, during the capture phase itself. As you navigate through the site, you'll witness the magic of Augmented Reality (AR) as each tag is automatically recognized and matched with the corresponding GCP you’ve measured.

This innovative feature not only saves precious time but also significantly reduces the margin of error, predominantly originating from manual input. By automatically marking every visible tag across multiple images, the algorithm ensures precise accuracy in GCP representation. This is a great contrast to manual methods, where user fatigue often leads to fewer marks and potential inaccuracies. With Tag Detection, Pix4D proudly offers a solution that meets user needs and redefines the limits of photogrammetric mapping.

To see Tag Detection in action and appreciate its full potential, we invite you to watch the video below. Witness firsthand how this feature is reshaping the landscape of GCP workflow, making it more intuitive, efficient, and user-friendly than ever before.

How Does Tag Detection Work?

Embarking on a journey with PIX4Dcatch's Tag Detection feature is like stepping into a world where accuracy meets efficiency. Let’s walk through the steps to fully leverage this revolutionary feature:

Step 1: Set the scene with Ground Control Points (GCPs)

Begin by strategically placing your tags on the ground. These GCPs are the backbone of your mapping accuracy, so ensure they are well-distributed across the area you intend to capture. Be careful not to position these at the edges of the scene as they will be only visible in a few images.

Step 2: Create a new Point Collection

Launch PIX4Dcatch and connect your GNSS rover. Then create a new Point Collection - this will be the repository where your GCPs will be organized and stored.

Step 3: Measure and record each GCP

Within your newly created Point Collection, it’s time to measure accurately and register each GCP. This step is crucial for ensuring the precision of your final model, as these points will serve as reference markers in your captured data. It’s also important to name each GCP with the number visible on the tag (EX:. PointName_1 will map to Tag 01)

Step 4: Activate Tag Detection

Ready for the magic? Tap the 'Tools' button located at the bottom of the app interface, next to the 'Capture' button. Here, you'll find the option to enable 'Tag Detection.' Once activated, select the Point Collection you wish to use. With just a few clicks, you're setting the stage for an automated, streamlined mapping experience.

Step 5: Start capturing your scene

Now, begin capturing your area of interest. As you move around with PIX4Dcatch, the Tag Detection feature operates in real-time, effortlessly identifying and associating each GCP tag with its corresponding point in your collection. In this real-time process, you can also view the tag label and keep track of the number of GCPs identified, ensuring comprehensive coverage and accuracy as you proceed.

Post-capture: fine-tuning for perfection

Once you’ve completed capturing, it’s time to refine. In the project capture view of PIX4Dcatch, you can review each GCP and, if necessary, manually adjust the markings, verify your marks, or even add or remove some as needed. This step ensures you have the utmost control over the accuracy of your GCP markings, a testament to the perfect blend of automation and user input, empowering you with comprehensive oversight of your project's precision.

Syncing to PIX4Dcloud or export to PIX4Dmatic

Upload your data directly to PIX4Dcloud for seamless integration. Your GCPs, precisely mapped by the Tag Detection feature, will automatically sync with PIX4Dcloud. Additionally, you have the option to export to PIX4Dmatic for further processing. In PIX4Dcloud, view the names and details of each GCP under the 'GCPs' layer, enhancing clarity and control over your project.

Need more details?

For those who want more in-depth instructions, or need to download the tags (A4/ US Letter) for the Tag Detection feature, a wealth of resources awaits. Visit our comprehensive support document: How to use automatic Tag Detection and manual GCP marking in PIX4Dcatch.