In short
Professional mobile photogrammetry reconstructs a 3D model from multiple photos, with no depth sensor or specialized hardware required. Unlike LiDAR or TrueDepth, it runs on a smartphone’s standard rear camera, across a wide range of iOS and Android devices. The result is a usable 3D model, with color and texture, suited to designing orthoses, compression garments, or supporting morphology tracking.
What is photogrammetry?
Photogrammetry is a 3D modeling technique based on photographic shots to determine the shape, dimensions, and position of an object in space. By using images taken from different angles, it geometrically recreates an object in three dimensions.
The method involves assembling successive images by identifying matching points between pixels, in order to reconstruct a model faithful to reality.
What are the types of photogrammetry?
- Analog photogrammetry: manual measurements from film photographs, now obsolete for professional use.
- Analytical photogrammetry: uses laser scanners and image-processing software to generate precise data.
- Digital photogrammetry: relies on advanced computing techniques to process digital images. It’s the method used in mobile 3D scanning, including in medical and O&P contexts.
How does mobile photogrammetry work?
Mobile photogrammetry works on a principle close to human vision: by capturing enough overlapping images from different angles, high-performance algorithms can reconstruct a three-dimensional model of the object, body part, or scanned area. To then obtain an object with the correct dimensions, a scaling process is required, combining the image capture with sensors and/or dedicated algorithms.
How do you perform a mobile photogrammetry scan with MyFit?
Step 1: image acquisition
A few dozen photos are generally needed to scan an area with sufficient detail. Stable lighting, a contrasted background, and keeping the subject still during the shots are all needed to guarantee a usable result.
Step 2: 3D modeling
The images are imported into photogrammetry software, which identifies common points between the views and reconstructs a 3D mesh: a structure made of many small triangles defining the object’s surface.
Step 3: post-processing
The generated model is then cleaned up: surface smoothing, removal of the background or unwanted elements, scaling, and calculation of the associated digital measurements.
What’s the difference between a 3D scanner and mobile photogrammetry?
A dedicated 3D scanner (LiDAR, Structure Sensor) generates a point cloud from a beam of light, generally with high precision but specific hardware required. Mobile photogrammetry relies on a series of photos taken from different angles, with no dedicated sensor — a relevant approach where access to a specialized scanner is limited or impractical, for example in a multi-site deployment.
What are the benefits of MyFit’s mobile photogrammetry for professional use?
- No specialized hardware: capture is done with a smartphone’s standard rear camera, with no depth sensor or accessory to buy.
- Cross-platform compatibility: unlike TrueDepth (limited to Apple devices with Face ID) or the Structure Sensor (an iPad accessory), photogrammetry works across a wide range of iOS and Android devices.
- Color and texture rendering: the generated model retains the colors and textures of the scanned area, useful for visualization and analysis.
- Scalability: the absence of dedicated hardware makes it easier to deploy across multiple users, sites, or teams.
In exchange, this approach requires stable lighting and careful image capture to guarantee a usable result — a point of attention to build into the capture protocol.
LiDAR, TrueDepth, Structure Sensor, mobile photogrammetry: how do they compare?
No discussion of professional 3D scanning is complete without mentioning the Structure Sensor, a long-standing reference in the industry. Like TrueDepth, it relies on infrared-assisted stereoscopy, but it’s a distinct sensor: an independent hardware accessory, developed by Structure, that attaches to an iPad.
| Criteria | LiDAR (iPhone/iPad Pro) | TrueDepth (iPhone and iPad with Face ID) | Structure Sensor (iPad accessory) | Mobile photogrammetry (iOS and Android) |
| Principle | Time of flight (ToF) | Infrared-assisted stereoscopy | Infrared-assisted stereoscopy | Image processing via algorithms |
| Sensor type | Built into the device (Pro models only) | Built into the device (front camera) | Dedicated accessory, independent of the smartphone | No dedicated sensor: standard rear camera |
| Compatibility | iPhone Pro / iPad Pro | iPhone and iPad with Face ID | iPad | iOS and Android smartphones and tablets |
| Accessoire requis | None | Mirror, for professional use | Sensor attached via a bracket | None |
| Resolution | Low (~256×192 px) | Medium (~640×480 px) | High (up to 1040×1200 px) | Medium to high (configurable) |
| Applications | Large spaces, bulky objects | Human body, clinical use | Human body, clinical use | Human body, clinical use |
To go further, see our dedicated articles on LiDAR scanning and TrueDepth scanning.
What are the professional applications?
Mobile photogrammetry has applications across several O&P and medical contexts:
- Orthopedic insoles: scanning the foot collects digital measurements useful for designing custom insoles.
- Facial visualization: useful for morphological analysis or designing adapted devices (glasses, helmets).
- Compression garments: capturing volumes and circumferences helps fit a garment to the patient’s actual morphology.
- Torso monitoring: 3D capture can support monitoring certain deformities such as scoliosis, alongside a reference medical examination.
These applications extend to other body areas (hand, head, torso, leg) depending on the professional’s needs.
FAQ on mobile photogrammetry with MyFit
It provides 3D models and digital measurements usable for designing custom devices and for morphology tracking.
LiDAR uses a dedicated sensor to measure distance via time of flight. Photogrammetry reconstructs a 3D model from multiple photos, with no depth sensor, which makes it compatible with a wider range of iOS and Android devices.
No. Unlike LiDAR or TrueDepth, photogrammetry doesn’t depend on a specific sensor and works on a wide range of iOS and Android smartphones equipped with a standard rear camera.
Designing orthoses and orthopedic insoles, compression garments, size recommendation, morphology tracking, and more broadly any need for custom digital measurement.
