[SOLVED] Receive image via MQTT (as binary)

Add-ons Bindings
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1

I have a Raspberry Pi that publishes an image via MQTT message to my local MQTT broker (mosquitto). This one bridges the communication to another broker running on an Amazon AWS EC2 instance. Using an MQTT Dashboard app on Android I can view the image while being not at home.

Now I want to integrate this image into the OH dashboard. I have tried to create an item:

Image mqttRaspberryPiImage "Pi Image" {mqtt="<[mosquitto:/raspberrypi/img:state:default]"}

But this leads to the following exception in the log:

2018-02-07 20:15:59.410 [ERROR] [el.item.internal.GenericItemProvider] - Binding configuration of type 'mqtt' of item 'mqttRaspberryPiImage' could not be parsed correctly.
org.eclipse.smarthome.model.item.BindingConfigParseException: cannot process unknown item type Image
	at org.openhab.core.binding.internal.BindingConfigReaderDelegate.getOpenHABItem(BindingConfigReaderDelegate.java:87) [207:org.openhab.core.compat1x:2.2.0]
	at org.openhab.core.binding.internal.BindingConfigReaderDelegate.getOpenHABItem(BindingConfigReaderDelegate.java:57) [207:org.openhab.core.compat1x:2.2.0]
[...]

As the stacktrace reveals, I am using OH 2.2.0.

Do I interpret the error message corretly, that the MQTT binding does not support images?

Unfortunately the MQTT dashboard app on my smartphone does not support base64 encoded images. The image has to be in binary raw format in the message body.

Do you have an idea how to solve this?

2

That is how I read it.

Create a little Python app or the like to receive the image and save it to the html folder in your config folder (/etc/openhab2/html for installed OH). Then you can use the Image element on the sitemap to bring up the image.