Look up was a project exploring thermal projections. It was installed in the Urban Room at UCL East as “Heat Trace” part of a collaboration with Henrietta Williams and her Testing Ground exhibition hosted in the UCL Urban Room at UCL East. Thermal imaging, also known as infrared imaging, allows us to visualize and capture thermal energy emitted by objects in the form of heat. By detecting these temperature variations, thermal cameras provide a unique perspective that extends beyond what our naked eyes can perceive. This ability to see the invisible heat signatures makes thermal imaging invaluable across a multitude of industries and applications.
The project used a Lepton FLIR camera which is a compact and versatile thermal imaging solution that brings professional-grade thermal imaging capabilities to a broad range of consumer applications. The Lepton camera integrates an advanced microbolometer sensor that captures infrared radiation with high precision and allows us to visualise the invisible.
The microbolometer sensor consists of an array of 80x60 tiny thermal detectors. These detectors can sense the infrared radiation emitted by objects in the form of heat which translates to a “pixel” value. Each “pixel” measures the temperature of the corresponding portion of the scene being captured. The temperature readings are converted into electrical signals proportional to the detected heat energy. After some internal signal processing to amplifying, filter, and digitize the signal, algorithms reconstruct the “pixels” into a thermal image.
Since thermal imaging captures temperature differences rather than colors, a color mapping scheme is applied to the thermal image to enhance its interpretability. This involves assigning different colors or color gradients to different temperature ranges, creating a pseudo-color representation of the thermal data. The color mapping allows users to easily distinguish and analyze temperature variations within the scene. In this example we use the “White Hot” colour palette.
Look Up demonstrates the capabilities of the FLIR Lepton when connected to a low cost Raspberry PI single board computer utilising the pylepton library to control the camera via Python. An overview of the code used is described on GitHub.
Photos from the installation are on Flickr:
Previous projects with thermal cameras also include some work whilst at Arup on the Millenium Bridge: