One of the typical building and restoration application is represented by the plaster or tiles detachments.
Advanced image manipulation techniques in building and restoration
Theoretically, those are activities quite simple under the condition to have with you the proper IR camera, for images that require in any case a good (or optimal) spatial resolution, required to “see” the details.
A good sight sense is required in any case, especially during the analysis.
If you’re tooled with the right IR camera it’s just a question to find the best weather conditions, go on site and wait, when you’re inspecting outdoor.
Everything will automatically appear, under the effect of the solar load. It will be your responsibility, with you experience and a perfect thermal tuning, to find the problems.
However, in the life of a thermographic inspector a more complex analysis can be requested. An analysis where the normal classroom preparation couldn’t be sufficient.
I say this because very often I meet colleagues that have not enough familiarity and practise with active thermography techniques and advanced imaging analysis techniques, all aspects that should be in the skills of any level II certified thermographer.
Let’s imagine that a Customer has required an evaluation of the condition of some stuccos in his amazing 19th century villa, that have been already restored. For those restoration activities the owner has some doubts and wonder if, together his expert, new restoration activities will be required.
The roof is complex, with wooden structure. The house is equipped with an automated temperature and humidity control system and the restoration expert pretend that the temperature inside is kept constant, inside (there are other masterpieces, in the house)
The only allowed modification is to open the windows for half an hour, at maximum, being a warm afternoon, in March. This thermal shock has been considered acceptable.
Perfect, you can say, but now, what to do?
Well, you can get a good IR camera, put it on a tripod and start shooting in time lapse mode.
Following the theory, you will open the windows and start looking the images to see what happens, to understand if, during the cooling down, something appears.
When you’ve taken some images, let’s say about a hundred, you should start to look at the anomalies, and here the problems start.
Even expecting to have a perfect eye, the evaluation can be really difficult.
If you’ve done everything in a perfect way and you are organised for an advanced image manipulation, everything can change.
Do you know how much??
So, I will show you.
The attached IR images represents both the last image of the time lapse shooting.
In the first case the image is observed with the usual method, in the second with an advanced image manipulation algorithm, with an R&D software.
IR image without advanced image manipulation
In the following videos you can find the time lapse sequences using the standard analysis method and the advanced one.
(I apologise for the low video resolution).
Time lapse of cooling phase (without advanced analysis)
Time lapse of cooling phase (with advanced analysis)
As you can see, in case of advanced analysis, small defect that are almost invisible to the human eye can be easily highlighted, even very small cracks.
If you need further explanations, we will be happy to clarify all your doubts.