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Schematics of the Phone Cam Array. To avoid clutter, only a single phone mount, mount cable tie adaptor and junction box are pictured. The width of the assembled frame is approximately 61 cm.
Source publication
Photogrammetry is a 3D reconstruction technique using photographs of the target from multiple angles. Taking pictures around a static object with a single camera can yield high-quality models, but if the subject moves between images, 3D reconstruction might fail. One way to mitigate this is to use multiple cameras.
This project aimed to develop a t...
Contexts in source publication
Context 1
... The 3D-printed phone mounts are attached with cable ties. A simple modular system of Android phones to capture images concurrently for photogrammetry reconstruction. The phones do not need to be the same model or make. The phones are attached to a 3D-printed handheld frame. The system allows the 3D reconstruction of living, moving subjects. Fig. 1 shows the basic construction of the Phone Cam Array. The phones are attached to the circular 3D-printed frame with cable ties. Each phone needs a phone mount and a junction box. All the cameras are released with a single button on the control grip, which houses the battery for the system as well. This proof of concept is composed of ...
Context 3
... 14 (2023) e00438 2. The circuit of the control grip follows a very simple design, the JST-XH connectors are connected to the battery with the switch inserted (Fig. 11A). The assembled version is shown in Fig. 11B. 3. Solder the two JST-XH female connectors to the JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector ...
Context 4
... 14 (2023) e00438 2. The circuit of the control grip follows a very simple design, the JST-XH connectors are connected to the battery with the switch inserted (Fig. 11A). The assembled version is shown in Fig. 11B. 3. Solder the two JST-XH female connectors to the JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector panel with hot glue to its position (Fig. ...
Context 5
... is shown in Fig. 11B. 3. Solder the two JST-XH female connectors to the JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector panel with hot glue to its position (Fig. 12A) 6. Screw on the cover of the control grip with M4 screws. (Fig. 12B) A B C D ) with the assembled components (B.) Please note that it is recommended to solder the wires to the switch first, then screw it into the grip ...
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... JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector panel with hot glue to its position (Fig. 12A) 6. Screw on the cover of the control grip with M4 screws. (Fig. 12B) A B C D ) with the assembled components (B.) Please note that it is recommended to solder the wires to the switch first, then screw it into the grip ...
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... of the frame 1. Insert the necessary heat-set inserts into the printed frame parts (Fig. 13) 2. Assemble two frame parts and the grip or control grip with the M4*20 mm countersunk screws (Fig. ...
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... of the frame 1. Insert the necessary heat-set inserts into the printed frame parts (Fig. 13) 2. Assemble two frame parts and the grip or control grip with the M4*20 mm countersunk screws (Fig. ...
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... Then connect the next junction boxes to the previous ones, until all of them are interconnected (Fig. 2B.). Both the control grip and the junction boxes have two JST-XH connectors, they are identical. 4. Secure the connecting cables with electrical tape (Fig. ...
Context 11
... reconstruction of 3D models can be performed with specific software applications. The exact steps necessary for 3D reconstruction vary greatly between applications, it cannot be attempted to give a detailed description of each. Fig. 12. A. The internals of the control grip. B. The cover is installed on the control grip. Fig. 13. Position of the heat-set inserts of the frame. The optional attachment points can be used for vertical ...
Context 12
... reconstruction of 3D models can be performed with specific software applications. The exact steps necessary for 3D reconstruction vary greatly between applications, it cannot be attempted to give a detailed description of each. Fig. 12. A. The internals of the control grip. B. The cover is installed on the control grip. Fig. 13. Position of the heat-set inserts of the frame. The optional attachment points can be used for vertical ...
Context 13
... phones used in this proof-of-concept project are listed in Table 1. The Huawei phones are current mid-range models, the Samsung is an old flagship, while the Oukitel is an old, entry-level one. To measure the time delay of the different cameras, pictures were taken of an iPad screen running the stopwatch (Fig. 17). A constant trend was that the Samsung took the images first, it was followed by the Huaweis and the Oukitel was the slowest. At the initial measurements, its average delay compared to the Samsung was almost 1 s (966 ms). The simple tweak of turning on the continuous autofocus mode of the Oukitel decreased the delay significantly to ...
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... 3D models from both image sets were created with ReCap Photo (Fig. 18A and B). To quantify the dimensional accuracy of the models, known dimensions (10 mm segments on the rulers) were measured virtually within ReCap Photo. Thirty segments were measured on both models by a volunteer, who did not know which model was created with the multicamera Table 1 Phones used in this pilot project. * The resolution of the ...
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... Fig. 17. Testing the release lag between the cameras. The frame is an early prototype, the circuits are as described in the paper. array. Statistical analyses were performed with GraphPad Quickcalcs (Dotmatic). The means of the two models (Table 3) did not differ significantly (t-test, p = ...
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... capture takes a shorter time, decreasing the chance of motion artefacts appearing. To assess the artefacts caused by breathing movements, another set of images was taken, with the same setting as described above, but the subject was asked to breathe normally. Normal breathing movements of the chest caused artefacts when a single camera was used (Fig. 18C), while the one taken with the camera array did not suffer from this (Fig. ...
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... To assess the artefacts caused by breathing movements, another set of images was taken, with the same setting as described above, but the subject was asked to breathe normally. Normal breathing movements of the chest caused artefacts when a single camera was used (Fig. 18C), while the one taken with the camera array did not suffer from this (Fig. ...
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... the main aim was to create a multicamera system for wound and injury documentation. To illustrate this, the handheld camera array was used to take several images of two cadavers with external injuries as a proof of concept. The images (32 photos in the case of the leg and 40 photographs in the case of the arm) were taken as shown in Fig. 2A. Fig. 19 illustrates, that this system was able to capture images for high-quality 3D model reconstruction. Two forensic medical experts were asked to describe the injuries based on the cadavers, then later based on the 3D models. The experts gave the same descriptions and reached the same conclusion regarding the mechanisms of ...
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... array is built, the devices might block available light. It could be countered by attaching LED strips to the vertical rods of the frame. Manufacturers omit the 3.5 mm jack from current-generation phones. USB C to 3.5 mm jack adapters might be used, but compatibility issues can emerge, as manufacturers might implement the adapters differently. Fig. 18. Comparison of models created with a single phone (A.) and four phones (B.) of a living volunteer. The phone and the phone cam array were handheld. The subject was asked to breathe lightly during taking images for A. and B. models. When the subject breathed normally, the movement of the chest caused an artefact when a single camera was ...
Context 20
... The 3D-printed phone mounts are attached with cable ties. A simple modular system of Android phones to capture images concurrently for photogrammetry reconstruction. The phones do not need to be the same model or make. The phones are attached to a 3D-printed handheld frame. The system allows the 3D reconstruction of living, moving subjects. Fig. 1 shows the basic construction of the Phone Cam Array. The phones are attached to the circular 3D-printed frame with cable ties. Each phone needs a phone mount and a junction box. All the cameras are released with a single button on the control grip, which houses the battery for the system as well. This proof of concept is composed of ...
Context 22
... 14 (2023) e00438 2. The circuit of the control grip follows a very simple design, the JST-XH connectors are connected to the battery with the switch inserted (Fig. 11A). The assembled version is shown in Fig. 11B. 3. Solder the two JST-XH female connectors to the JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector ...
Context 23
... 14 (2023) e00438 2. The circuit of the control grip follows a very simple design, the JST-XH connectors are connected to the battery with the switch inserted (Fig. 11A). The assembled version is shown in Fig. 11B. 3. Solder the two JST-XH female connectors to the JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector panel with hot glue to its position (Fig. ...
Context 24
... is shown in Fig. 11B. 3. Solder the two JST-XH female connectors to the JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector panel with hot glue to its position (Fig. 12A) 6. Screw on the cover of the control grip with M4 screws. (Fig. 12B) A B C D ) with the assembled components (B.) Please note that it is recommended to solder the wires to the switch first, then screw it into the grip ...
Context 25
... JST connector PCB or a prototype PCB. 4. Solder the cables to the switch, then screw it to the control grip. 5. Connect the shutter release button with the 9 V battery terminal and the JST connector panel by soldering. Fix the JST connector panel with hot glue to its position (Fig. 12A) 6. Screw on the cover of the control grip with M4 screws. (Fig. 12B) A B C D ) with the assembled components (B.) Please note that it is recommended to solder the wires to the switch first, then screw it into the grip ...
Context 26
... of the frame 1. Insert the necessary heat-set inserts into the printed frame parts (Fig. 13) 2. Assemble two frame parts and the grip or control grip with the M4*20 mm countersunk screws (Fig. ...
Context 27
... of the frame 1. Insert the necessary heat-set inserts into the printed frame parts (Fig. 13) 2. Assemble two frame parts and the grip or control grip with the M4*20 mm countersunk screws (Fig. ...
Context 28
... Fasten the phone mount and the junction box to the frame with two cable ties (Fig. ...
Context 29
... Then connect the next junction boxes to the previous ones, until all of them are interconnected (Fig. 2B.). Both the control grip and the junction boxes have two JST-XH connectors, they are identical. 4. Secure the connecting cables with electrical tape (Fig. ...
Context 30
... reconstruction of 3D models can be performed with specific software applications. The exact steps necessary for 3D reconstruction vary greatly between applications, it cannot be attempted to give a detailed description of each. Fig. 12. A. The internals of the control grip. B. The cover is installed on the control grip. Fig. 13. Position of the heat-set inserts of the frame. The optional attachment points can be used for vertical ...
Context 31
... reconstruction of 3D models can be performed with specific software applications. The exact steps necessary for 3D reconstruction vary greatly between applications, it cannot be attempted to give a detailed description of each. Fig. 12. A. The internals of the control grip. B. The cover is installed on the control grip. Fig. 13. Position of the heat-set inserts of the frame. The optional attachment points can be used for vertical ...
Context 32
... phones used in this proof-of-concept project are listed in Table 1. The Huawei phones are current mid-range models, the Samsung is an old flagship, while the Oukitel is an old, entry-level one. To measure the time delay of the different cameras, pictures were taken of an iPad screen running the stopwatch (Fig. 17). A constant trend was that the Samsung took the images first, it was followed by the Huaweis and the Oukitel was the slowest. At the initial measurements, its average delay compared to the Samsung was almost 1 s (966 ms). The simple tweak of turning on the continuous autofocus mode of the Oukitel decreased the delay significantly to ...
Context 33
... 3D models from both image sets were created with ReCap Photo (Fig. 18A and B). To quantify the dimensional accuracy of the models, known dimensions (10 mm segments on the rulers) were measured virtually within ReCap Photo. Thirty segments were measured on both models by a volunteer, who did not know which model was created with the multicamera Table 1 Phones used in this pilot project. * The resolution of the ...
Context 34
... Fig. 17. Testing the release lag between the cameras. The frame is an early prototype, the circuits are as described in the paper. array. Statistical analyses were performed with GraphPad Quickcalcs (Dotmatic). The means of the two models (Table 3) did not differ significantly (t-test, p = ...
Context 35
... capture takes a shorter time, decreasing the chance of motion artefacts appearing. To assess the artefacts caused by breathing movements, another set of images was taken, with the same setting as described above, but the subject was asked to breathe normally. Normal breathing movements of the chest caused artefacts when a single camera was used (Fig. 18C), while the one taken with the camera array did not suffer from this (Fig. ...
Context 36
... To assess the artefacts caused by breathing movements, another set of images was taken, with the same setting as described above, but the subject was asked to breathe normally. Normal breathing movements of the chest caused artefacts when a single camera was used (Fig. 18C), while the one taken with the camera array did not suffer from this (Fig. ...
Context 37
... the main aim was to create a multicamera system for wound and injury documentation. To illustrate this, the handheld camera array was used to take several images of two cadavers with external injuries as a proof of concept. The images (32 photos in the case of the leg and 40 photographs in the case of the arm) were taken as shown in Fig. 2A. Fig. 19 illustrates, that this system was able to capture images for high-quality 3D model reconstruction. Two forensic medical experts were asked to describe the injuries based on the cadavers, then later based on the 3D models. The experts gave the same descriptions and reached the same conclusion regarding the mechanisms of ...
Context 38
... array is built, the devices might block available light. It could be countered by attaching LED strips to the vertical rods of the frame. Manufacturers omit the 3.5 mm jack from current-generation phones. USB C to 3.5 mm jack adapters might be used, but compatibility issues can emerge, as manufacturers might implement the adapters differently. Fig. 18. Comparison of models created with a single phone (A.) and four phones (B.) of a living volunteer. The phone and the phone cam array were handheld. The subject was asked to breathe lightly during taking images for A. and B. models. When the subject breathed normally, the movement of the chest caused an artefact when a single camera was ...
