EinScan H - "Face Scan" mode

This article was created based on software EXScan H v1.0.5.3


Face Scan mode is specifically designed for scanning human faces or body, including hair.


This operation mode makes use of the invisible infrared light projector, which not only enables scanning hair, but its invisible light results in a comfortable and not invasive process for the subject being scanned.


The IR projector emits at 940 nm, making it invisible for the human eye.



In this article we will be focusing on how to efficiently achieve the best results when scanning a full human body.


Face Scan mode is the operation mode for the IR projector, but it is not limited to scanning persons. This mode can also be used to scan objects sensitive to visible light, such as paintings, or hard to scan objects such as furry surfaces.

TABLE OF CONTENTS


Face Scan project settings


As usual, select Face Scan mode and create a new project.



After giving it a name and a location, the software will provide the following project settings:



The project settings for Face Scan mode permits selecting between:

  • Texture and Non-texture scan.
  • Alignment mode: either Features or Markers.
  • Resolution ranging from 0,5 to 3 mm.

Texture scan will activate the EinScan H LEDs, while Non-texture scan will work with the LEDs off.


Note that Texture scan disables the Marker alignment, and vice-versa. Therefore, Texture scan only operates with Features alignment.


The recommended project settings for scanning a full person are the following:


  • Texture Scan
  • Feature alignment
  • Medium Detail: 1 mm point distance should be sufficient to obtain a great result.


Face Scan interface


Once the project settings have been applied, the scan interface will appear.


A window pops-up. It contains instructions on how to scan a full body:



We will be following the numbered tips to successfully fulfil a full body scan.


So far, we can close the window. We will thoroughly describe the listed instructions below. 


The window above can be recovered any time. Simply click on Tips on the upper right corner of the screen.


The main scan screen appears:



Let's first focus on the scan settings on the left of the screen. These settings include:


  • Brightness: Depends on the ambient light and the texture of the subject being scanned.

  • Working distance (mm): Determines the scan range distance.

    Short distance provides great details, yet the scan range is smaller.
    Long distance provides lower details, yet the scan range is larger.

  • Texture flashing: this toggle button permits enabling/disabling the LEDs of the EinScan H.


     

 



A bright, indirect and smooth ambient light will provide the best texture results. If this is met, LEDs are not required for the operation.

In case the above is not met, or if the subject is sensitive to the light from the LEDs, please disable Texture flashing.



Selecting the Scan Settings and starting the Preview


1. Set Working Distance (mm) to short range


We are going to start the full-body scan by scanning only the face of the subject.


To obtain the best details, we are going to set the Working Distance (mm) settings at its shortest range: 200 - 400 mm.



2. Start the Preview mode


To enter the Preview mode, click the PLAY button once, either on the software GUI or on the back of the scanner.



3. Adjust the distance to the subject


Point the scanner to the subject and adjust the distance.


The scanner is equipped with a distance indicator light, which will change its light colour according to the distance:

  • Blue: Too far
  • Green: OK
  • Red: Too close

The distance can also be checked anytime on the left side of the software UI, on the left side:


If the Working Distance (mm) is set to 200-400 mm range, the distance should be optimal at around 300 mm.


4. Adjust the brightness


Once the scanner is within the optimal (green) distance, adjust the brightness by clicking the camera brightness buttons on the button pad.


 

Adjust the brightness until small scattered red areas are visible on the camera view.


You will notice that brightness is also correct, because the Scan Preview will show more data. See the example below:



Scanning a person


5. Start scanning the face


Press the PLAY button again to start acquiring data. Move the scanner evenly and steady. Avoid moving too fast.


Since eyes and facial expression are likely to move, we will tackle that first.


Start scanning to cover the face, including the forehead, temples and ears.


Raise the scanner and scan the face from above, to make sure all corners are covered.


Afterwards, turn the scanner horizontally  use this orientation to scan from below. Make sure to scan the nostrils, chin and neck as well. 


Last but not least, scan part of the chest and shoulders. They will be useful in next step.



Once complete, pause the scan. The subject being scanned should still not move.


6. Scan the hair and the rest of the body


The face and part of the chest and shoulders have been scanned. It is time now to set the Working distance (mm) settings to long distance: from minimum to maximum distance, that is, from 200 to 1500 mm.



The scan range becomes larger, thus increasing the speed of the scanning process. This will ease scanning the rest of the body, including hair.


Note that, with the Working distance (mm) settings above, the optimal (green) distance should be around 850 mm.


6.1. Scan the hair


Start the preview and point to the shoulders, scanned in the previous step, so the software can recover the tracking.


Begin the scan from the shoulders and move the back while scanning the head and hair of the subject. Since the head might not be a big enough surface for maintaining the tracking, shoulders and back will help on maintaining the alignment.


Scan as long as required to acquire as much data as possible.


At this stage, since Working distance (mm) settings is set to long, try not to re-scan the face of the subject to ensure the best details of this already scanned region.



6.2. Scan the body


At this point, the rest of the body can be scanned.


It is recommended to divide the scanning of the body into sections. Scan each one, from top to bottom, before moving to the next one.


Note: The body position here used is only for display purposes.
We recommend keeping the arms joined along the body, to make sure they do not move during the scan.
If suspended arms or legs are desired, it is recommended to make use of accessories that help the subject holding them.



Wrapping up: video of the full process


Below you can find the video of the full suggested process:



Tips and further advice


1. Scanning the eyes


Eyes are likely to move during the scan process. Either because the subject might blink, or because the subject might stare at different directions during the process.


The above might lead to undesired effects, like the ones below:


  • Eyes staring at different positions during the scan of the face:


  • Blinking might cause capturing one or both eyes closed:


For this reason it is important to scan them at the very beginning of the process, quickly and with as little delay between them as possible .



The optimal level of brightness does not only depend on the ambient light of the set, but also on the textures of the surface being scanned.


That means, that the brightness level demand might vary during the scanning process.


For instance, while being the brightness level set for scanning fair skin, it might not be suitable for scanning black hair.



The same will occur if the subject is wearing, for example, light and dark clothes.


Use the brightness increase/decrease buttons on the scanner button pad to adjust its level while scanning.


3. Hairstyles


The subject's hairstyle is another important thing to consider prior to beginning to scan.


Light needs to reflect on hair so the scanner can detect it. 

It should thus form a sufficiently large surface that can bounce the light from the IR projector back to the scanner cameras.


Therefore, spiky hair, the ends of the hair, thin tufts of hair... are difficult or even not possible to scan since the light cannot reflect there.

It is then advised to comb the hair to obtain a even, smooth surface:


Difficult to scanGood to scan


4. Find a comfortable position for the subject


The subject being scanned should not move along the process of scanning.


Therefore, it might be convenient to adopt a comfortable position that can be easily hold as long as the process lasts.


In case that a position which requires arms or legs being suspended is required, it is suggested to make use of accessories that can work as supporting points for the subject, which can be deleted from the scan afterwards.


5. Ensure enough room to scan


To cover the whole subject's body, you will need to move around the subject 360°.


Considering the scanner's working distance, you should ensure enough room at a radius of 1,5 meters from the subject.


It is thus suggested to plan ahead the necessary space prior to starting the scan.


This way you make sure you will have enough room to move around and reach all the areas you wish to scan, and that the process won't be interrupted.


6. Mind the cable


It is worth bearing in mind that the scanner is connected to a PC by a cable.


Despite this cable being long enough to ensure that the operator can freely move around the subject, avoid following paths that can tangle the cable, such as walking in circles around the subject always in the same direction.

7. Let the software work


Before meshing, Point Cloud data will be displayed raw. This visualization might be far from the final result.



Wait until the data is meshed to evaluate the output of the scan.


8. Practice


The process above suggested is a theoretical description of the steps to take to successfully approach a scan of this nature.


However, in practice different challenges may appear.


Experience is here the most valuable skill, and it is only achievable through practice.


9. Communicate with the subject


Last but not least, it is important to have a good communication with the person being scanned.


Explain him/her the process: prior to scan, explain what steps are to be taken and what is he expected to do. Additionally, update him along the scanning process.


For instance, explain him/her to try not to blink and to stare always at the same point when scanning the face.

Likewise, since the face should not be re-scanned, tell him that he/she can blink and stare somewhere else once the face has been scanned.


A good cooperation with the subject being scanned will definitely help achieving a great scan.


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