thermal-visual-msx-image

If you are taking thermal images of various things you should be well aware of the fact that while thermal images do show the temperature of objects they do little to provide easy visual cues to what part of the object is hotter or colder. The reason is that thermal images just record the temperature information of objects and while this can create somewhat of an outline of the object you are examining, if you do not take a visual image to store with the thermal image later on you might have trouble identifying things on the thermal image. Not all thermal cameras ca do that – record both thermal and visual images, but even if your camera does not support that (like our FLIR i7 for example) you can still do pretty well if you use a digital camera or your smartphone to also take a visual image as a reference.

Thermal MSX (Multi Spectral Dynamic Imaging) images is what FLIR calls their mode of overlaying both thermal and visual images together and processing the data in order to provide a more detailed thermal image and this mode does work very well as you can see on the sample image above. Even with lower resolution thermal image when you overlay on top of it a visual image and combine the two to have the outlines of the objects you are shooting the end result can be really good. On this thermal photo we have recorded the temperature of an Mitsubishi Air-conditioning system in operation shot with the FLIR ONE thermal camera accessory for iPhone. Even though the FLIR ONE is with a low resolution thermal imaging sensor when we combine the thermal with visual information the resulting thermal MSX image does look really good as it can give both useful thermal and visual information, especially if the goal of the image is to be more understandable to people that are new to thermal imaging.

Taking MSX thermal images (overlaid visual and thermal data) however is not possible all the time as taking a good image in the visual light spectrum does require you to have good light conditions, unlike thermal images that can be taken even during total darkness. So make sure that you have enough light available when you need to take MSX thermal images if you have a thermal camera capable of this as not all models can do this, but as we’ve explained you can help yourself by taking manually a visible spectrum photo with the help of your smartphone or digital camera.

thermal-camera-sensor-resolution-comparison

Thermal cameras do come with various sensor resolutions with the more expensive the camera is, the higher resolution it usually provides for the thermal images you can record. The affordable thermal cameras usually do come with low resolution sensors that also have a more limited thermal detection range, so they cannot detect very low or too high temperatures. Usually when your thermal imaging sensor is with a certain resolution you can double it with software image interpolation to get a higher resolution image to make things more visible without issues. But the better and higher the resolution is, the easier it is to see what you are looking for as normally thermal images do not provide very good reference for the actual objects being shot. On the image above you can see a sample of how a thermal image will look like if you are using a 16×16 pixel thermal imaging sensor all the way up to 640×480 resolution sensor. Do note that each step up from 80×60 is double the resolution, but comes with essentially 4 times the pixels and 640×480 thermal imaging sensors are something you can normally find in very high-end products only, so most of the time you need to use lower resolution thermal images and there interpolation may help.

therm-app-thermal-camera-accessory-for-android

When we are talking about a thermal camera that is designed to be used together with a smartphone or a tablet we presume that it needs to be a low-end and affordable solution. Well, that is not always the case as we can see with the Therm-App from the Israeli company Opgal. The main goal of the Therm-App accessory for Android mobile devices is to turn smartphones into powerful thermal cameras, featuring high-resolution thermography and long range, enhanced night vision capabilities. The Therm-App comes with a thermal imager with a resolution of 384×288 pixels that previously was only available on standalone professional thermal imaging cameras and thermography devices. The lightweight and compact Therm-App device fits multiple phone models. It can also be mounted on any tripod or camera handle using its standard connector. With its interchangeable lenses system, the Therm-App device provides effective detection of faraway targets through its long range (19mm) lens, and a wider view through its 6.8mm lens. Its 8.7Hz FPS version is export license free. The only thing that you might not like much about this accessory is the price, it is currently available for $1600 USD, though for the resolution and features it offers you canot expect it to be very cheap.

therm-app-sample-thermal-images

Therm-App Specifications:
– Resolution: 384×288 pixels (>110k pixels)
– Spectrum: LWIR 7.5 -14um
– Enhanced Vision: High-resolution thermal imagery (grayscale day/night vision) NETD <0.07°C - Color temperature mapping: 5°C to 90°C - Available palettes: Rainbow, Iron, Grayscale - Lens And FOV: 19mm lens (19 x 14⁰) - Frame Rate: 8.7Hz - Operating Temperature: -10°C to +50°C (-4°F to +122°F) - Power Supply: 5V over USB cable - Power Consumption: Less than 0.5W - Certifications: CE, FCC - Device Attachment: Clip-on for smartphone (5-10cm span) - Mobile Platform Support: USB OTG (On The Go) compatible devices - Mobile OS Compatibility: Android 4.1 and up - Recording And Sharing: Therm-App Smartphone App plus any sharing App

Specifications wise there is one important thing worth mentioning that can be considered as a bit of a disadvantage – the temperature range that the thermal camera accessory can detect. The operating range of just 5 to 90 degrees Celsius is pretty limiting and with a larger resolution thermal imaging sensor we kind of expected to see a wider detection range available as well, especially considering the price of the Therm-App device. Other than that the device does look pretty cool with its design allowing the user to also swap lenses depending if a longer or shorter detection range is required – based on the kind of use you are planning to go for. The sample thermal images captured with the high resolution thermal imaging sensor do look very nice in their original resolution and with some interpolation they they be perfect for use for visualizations and thermal reports, that is if the temperature range of the Therm-App is enough for your needs.

For more details about Opgal’s Therm-App thermal imaging accessory for Android…

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