Capturing

katrinhumal edited this page Sep 29, 2016 · 54 revisions
  1. What to capture
  2. What not to capture
  3. How to take great photos
    1. Streets and roads
    2. Corners
    3. Facades
    4. Interesting places
    5. Objects
  4. Different modes to capture
    1. Driving
      1. Mounting the phone
      2. Glare from dashboard
      3. Battery and memory
      4. Tips for capturing
      5. Alternative setups
    2. Cycling
    3. Walking
    4. Panorama
    5. Portrait mode
  5. Data and storage
    1. Storage requirements
    2. Upload

What to capture

Try to get clean unobstructed views of:

  • Streets, bike paths, pedestrian paths (in the direction of the road/path).
  • Buildings (front facade view).
  • Views (anything noteworthy or interesting about a place).
  • Squares, parks and open areas.

Most times, taking photos in the direction you are moving, of the road in front of you, is the best view. In some cases a side view can be more interesting. You decide. There is no limit on the level of detail, you can take as many photos as you like. You may find some inspiration from our community in this blog post or by taking a look at our community page.

What not to capture

We want to protect the privacy and integrity of our fellow neighbors. Avoid taking photos with lots of people in them. Definitely avoid photos where you can clearly identify people.

We are continuously improving our algorithms to automatically detect faces and license plates to blur them, and to give you the possibility to hide and flag images.

Mapillary reserves the right to remove any questionable content. Please avoid:

  • Close-ups of people
  • Close-ups of private property through fences etc
  • Private and restricted areas (unless they are your own and you really want to share them)
  • Military and other sensitive areas

How to take great photos

The main thing when capturing is to keep on moving and to try and hold the camera itself still, regardless of whether you're walking, cycling or driving (more on those methods below).

The ideal environment for a Mapillary sequence is to have the sun behind you, minimal traffic and fewer people about.

We use a technology called Structure from Motion (SfM) to create an immersive experience when you're viewing the sequences. For SfM to work its best, follow these tips when taking photos:

  • Take many photos in one sequence (at least 10, but the more the better)
  • Try to have overlap in the photos - this will work well to demonstrate motion from one photo to an another
  • Forward motion in the direction of travel is the most immersive for the viewer
  • Taking overlapping photos of an object from various angles will allow 3D-like viewing with further developments to SfM
  • Orientate the camera at a level angle and in landscape mode

That is how we end up with seeing something like this.

Here are some more tips for capturing different things.

Streets and roads

When your want to cover a street make sure the camera is pointed in the direction of the street. If you have time, first cover one direction and then the other. When that is done you can orientate the camera left or right to the direction of travel.

Streets

Corners

When walking around corners it is best to take more photos with lots of overlap to create smoother transitions. Selecting manual mode or adjusting the frequency of automatic capture can help achieve this.

Corners

Facades

To capture facades, point the camera to the left or right towards the direction of travel. This works best when the street is wide enough so the large part of the facades are visible and you are moving slowly.

Facade

Interesting places

For interesting locations you can consider panorama mode which provides a nice viewing experience. This is a particularly useful tool to photograph street intersections, but also for spectacular views.

Panoramas

Objects

To capture a single focal point such as a statue or a small structure, orbit around it taking pictures at different angles.

Objects

Different modes to capture

Driving

Mounting the phone

First and foremost, when capturing in a car, a mount of some sort is required to hold the phone steady and in a position close to the windshield. If you do not have one, send us a request through this form and we will get one out to you.

Here's a good example of positioning the car mount so the phone has a clear view of the road with no parts of the car showing: Mounting the car mount

Glare from dashboard

The angle of your dashboard and the glass will alter the lighting and affect the glare on your capture device. Try a few different positions until you get it right for your car. High up close to the rear view mirror is usually a good spot. Our users have also shared two great tricks to fight glare using black felt or a DIY-polarizer.

The black felt trick

Some users have figured out that covering the dashboard with black felt helps to reduce the glare problem. Below is an example from our Ambassador Elliott (talllguy).

Fighting glare with black felt

On a sunny day

The self-made polarizing filter

Another option is to try to make your own circular polarizing filter (CPF). Here is a tutorial from our community member descilla.

There is a way to get a CPF for (nearly) free. All you need are 3D glasses from the cinema (usually disposable articles). If you are not passionated in watching movies you might have to ask a friend (some people have "thousands" of them at home).

Detail note: Some cinemas are using other technologies than Polarized 3D system4 and won't work therefore.

Follow these (trivial) steps to get your CPF:

  • Detach one of the lenses of the 3D glasses.
  • Place it in front of your (mobile phone) camera.
  • Aim at a window (with a lot of reflections).
  • Rotate the lens (of the 3D glasses) in front of your camera until you get the best result (sometimes you get better results when you turn the lens round).
  • Stick the lens with tape (or unicorn stickers).
  • This is what it looks like (if you want it to look neater then e.g. cut out a part of the lens, use "real" tape):

Phone with DIY CPF

Here you can compare before: Before DIY CPF

And after: After DIY CPF

(See also the original forum post about this.)

Battery and memory

For longer drives it is helpful to have a phone charger that you can plug into a cigarette lighter/USB port and if your device supports it, a microsd card to expand the memory of your capture device. The average file size on iOS devices for each image is about 2mb. This equates to about 3.6gb of storage every hour so you will need to ensure your device has enough memory and/or an external SD card. The average file size on Android devices is generally a bit bigger. If you have concerns about the space required, you can also reduce the resolution of the images in the settings or the frequency of capture.

Tips for capturing

When you are ready to capture, select riding mode by swiping in from the left on Android and tapping the walking icon or on iOS by tapping the icon. By default the app will lock the compass in the forward direction of travel which ensures a more accurate compass direction for the sequence.

Things to remember when using a car mount:

  • Avoid capturing in the rain as the sequences captured are generally of poor quality.
  • Remove lighter objects on the dashboard as they often reflect in the windshield.
  • Ensure the mount is not shown in the images being taken.
  • Avoid capturing during low light situations. Most cell phone cameras struggle to take good pictures in low light; doubly so when they're moving in a car.

Alternative setups

If you have an action camera such as the Garmin Virb, you can create your own dual camera setup by using your phone as the in-car capture device, positioning the Garmin externally to capture different angles. Mapillary user rps333 used his phone in the front of the car facing forwards and his Garmin facing backwards at a 30 degree angle to capture POI information. Facing the camera backwards was an easy way to avoid summer bugs interfering with capturing. Mounts such as these are useful for mounting action cameras to vehicles.

For those who are looking for a little DIY fun, one option would be to mount your device to the roof which will overcome any glare issues you have. One user mounted this Ikea box to the roof of their car, using rubber, bolts, nuts, and cork to reduce shock and vibrations. The sequences look great.

Cycling

Cycling is a fantastic way to cover long distances at a pace that allows you to see the scenery and capture some memorable sequences. It’s also a great way to keep fit.

Again it is important to have a mount for cycling and in this case a very study one that will keep the camera steady as the bike goes over rough surfaces. If you are using a phone, the best mounts are those that hold it horizontal/landscape relative to the ground so that the photos are an appropriate aspect ratio for Mapillary.

Here is the setup Jesolem uses with the Mapillary bike mounts, which you can request for your own use by sending us a request through this form.Mapillary bike mount

Without a decent mount, the shocks absorbed by the bike can lead to blurry photos. Road bikes are more susceptible to this than mountain bikes so an action cam may be best if capturing from a road bike regularly. Surfaces such as sand, gravel and dirt roads also cause blurring so keep this in mind and if possible, ride slowly over these surfaces. Making sure that your ride is not too fast or bumpy also decreases the risk that the phone could slide out of the mount and be damaged.

See our Mounts section for recommended mounts and setups.

When you are ready to capture, select riding mode by pressing the car icon. The default frequency for capture is every 2 seconds but this can be changed in the settings.

Once you have taken the sequence, review your photos in the app or on your computer if you are using another device and delete unwanted photos. Osric has written a fantastic blog post with tips on capturing whilst riding.

Walking

Capturing sequences as you walk is a great to way to capture the finer details of an area. The main thing to keep in mind is the angle you will be taking photos from. It is best to remain consistent. If you are capturing 0° then it is best to continue pointing the camera straight ahead so that the sequence can be played through.

When you are ready to capture, select walking mode by swiping in from the left. You can select either manual, which allows you to manually take a photo however frequently you feel necessary, or auto shot, which again will default to capturing a photo every 2 seconds. This can be adjusted in the settings to suit your needs.

Hold the camera horizontally and make sure to keep it relatively level. The tilt lines should assist with this. Some people prefer to rest the phone in a pouch around their neck which is also a good way to keep the phone level. You can go to settings and have the app lock the compass in the forward direction of travel. That ensures a more accurate compass direction for the sequence; however, it is based on the assumption that you keep your camera pointing forward so make sure not to sneak in any side views there.

If you are finding that your images are blurred, try stopping when you walk and resuming again once the photo has been taken. Manual capture mode is more suited to this method.

Panorama

Panoramas are the best way to capture those stunning vistas where you stop, look around and realise the view is worth sharing.

To select panorama mode, swipe in from the left and select panorama. The blue bars move to represent the area of the panorama you are capturing, while the the red bar is indicating North.

Mapillary supports any panorama that conforms to the Photo Sphere XMP Metadata standard. When you are viewing a panorama the viewer will change to a wider aspect ratio. Check out our blog post on panoramas for more information on what type of panoramas are supported.

Portrait Mode

For whatever reason, you may decide you wish to capture in portrait mode. Especially while riding, many mounts are more supportive of portrait mode than landscape. To enable portrait photos to be taken, you will need to uncheck the pause while tilting option in the settings. At this stage Mapillary is designed for images in the 4:3 aspect ratio however the new viewer supports portrait images. If you like, you can crop your images to the 4:3 ratio. Phatch is a useful tool for batch photo editing and best of all, it's open-source and available for Windows, Mac OS and Linux.

Data and Storage

Storage Requirements

Images are taken with the largest resolution, at 4:3 ratio. Depending on your device, one photo takes roughly 2-8MB, giving you about 1000-4000 photos if you have 8GB of free storage on your phone. The average file size on iOS devices for each image is a about 2mb, generally larger if you have an Android device so you may need an external SD card. The average file size on Android devices is generally a bit bigger. If you have concerns about the space required, you can also reduce the resolution of the images in the settings or the frequency of capture. Capture will be stopped when you have less than 10% free storage space left, or when your battery level is under 10%.

Device Average Image Size One hour
iPhone 6 2 MB 3.6 GB
HTC One X (2012) 2 MB 3.6 GB
Sony Xperia Z3 8 MB (1 MB in low res mode) 14.4 GB
Contour Roam Action Camera 1.7 MB 3.06 GB

To change the storage location of images captured with Mapillary, go to settings and scroll down to 'Developer'. Tap 'Storage location' and navigate to your micro-sd card or alternative storage location (note that this option is only available on Android devices). Photos are stored in the app folder and deleted after upload. Photos are never stored in your camera roll. The only way to view them is through the album view in the app.

Upload

Mapillary defaults to upload your photos when you are connected to wifi, not using your mobile data. For more information on the upload process, visit our dedicated upload section