Photo camera input

Who it’s for

Field technicians and inspectors who need to attach a picture to a device from the dashboard — proof an installation was completed, a photo of a damaged unit, a meter reading captured by camera. The photo has to end up on the entity, not in a separate system somebody has to cross-reference.

What it does

The Photo camera input widget takes a picture from the device’s camera or accepts an uploaded file, and stores it on the entity as a base64 value. Images are captured at up to 640 by 480 by default, encoded as PNG, and saved to the platform’s image gallery as well as onto the entity.

• Capture or upload — a webcam or phone camera on the spot, or an existing file where the photo was taken earlier.
• The image lands on the entity, as a server attribute or a telemetry value, so it travels with the device rather than sitting in a separate store.
• Images can be saved to the platform’s image gallery, which is what makes them reusable elsewhere on dashboards.
• Format, quality and maximum dimensions are all configurable, which matters because a base64 image is stored inline.
• A public gallery link can be produced for images that must be reachable without a login.
• The Photo camera input widget stores one image per configured key: a gallery of several photos per device needs several keys, or a different approach entirely.

How to set up

Data keys

The Photo camera input widget takes the key it writes from its datasource configuration.

Attribute	Scope	Operation	Description
Configured key	Server	Write	The captured image is written as a base64 string. A telemetry key can be used instead, which keeps a history of captures rather than only the latest.

Image

Setting	Default	Effect
Image format	PNG	JPEG, PNG or WEBP
Image quality	0.92	Compression level for the lossy formats; ignored for PNG
Maximum image width	640	Captures are scaled down to fit
Maximum image height	480	Captures are scaled down to fit
Save image	On	Also stores the capture in the platform’s image gallery
Public gallery link	Off	Makes the gallery image reachable without authorization

Switch the format to JPEG before deploying this anywhere photos are taken routinely. A PNG photograph is several times the size of the equivalent JPEG, and the value is stored inline on the entity rather than as a file reference.

How to customize

• To keep stored images small — set Image format to JPEG and tune the Image quality, which has far more effect than the dimensions do.
• To capture more detail — raise the Maximum image width and height, accepting the size cost.
• To keep every capture rather than only the latest — write to a telemetry key instead of an attribute.
• To reuse the photos elsewhere — leave Save image on so captures reach the image gallery.
• To share a photo outside the platform — turn on the public gallery link, remembering it makes the image readable by anyone with the URL.
• To caption the form — set the Widget title.

Tips

• Choose JPEG and a quality around 0.8 for anything photographic. PNG is lossless and correct for screenshots and diagrams, and dramatically wasteful for a photo of a meter — and the difference is multiplied by every device in the fleet.
• Think before turning on the public gallery link. It removes the authorization check on that image, which is a reasonable trade for a product photo and the wrong one for a picture of a customer’s site.