What do the colors mean in thermal imaging? Features of the operation of thermal imaging equipment and its scope. Options for using thermal imaging in practice. The most commonly used palettes, their color combinations and applications.
What do the colors mean in thermal imaging?
Thermal imaging optics is widely used throughout the world. It is actively used to perform a variety of tasks where it is necessary to find and identify various objects or objects in the dark. Thanks to thermal imaging, it is possible to obtain an image on which individual areas are marked with different colors. In order to be able to read such information and obtain the necessary data, you should study in advance what this or that shade means.
What is the meaning of the colors?
Thermal imaging is ubiquitous. It can be seen in dozens of films, hundreds of videos and thousands of photos from the Internet. Such a picture is initially understandable to everyone, but not everyone can correctly decipher it and extract the maximum of useful data. Therefore, before buying and using various thermal imaging devices, you should learn how to correctly read the information they give out. Only in this way will it be possible to exploit the equipment to the maximum and get a lot of benefits from it.
First of all, you should pay attention to the features of the operation of most thermal imaging devices. Each model sold does not use natural or artificial lighting to create an image of the area in question. Instead, the optics respond to heat waves that come from most surrounding objects. The strongest thermal studies are observed in animate beings and strongly heated objects, and the minimum – in cold objects.
The principle of operation of any thermal imager is quite simple. The sensors built into it collect heat emanating from various objects, and also remember their temperature. Further, thanks to special programs, the received data is processed and, on their basis, a thermal image is created, which is given to a person on the display of the device. This whole process takes a few fractions of a second, so a person does not have to wait long for the result. There are different types of software. The most primitive will allow you to get an image on which only objects that have one or another temperature are visible (only 2-3 colors). More modern software creates a multi-color image that allows you to assess the level of heating of a selected individual area of the object in question.
The thermal imaging equipment produced today gives the user a picture that displays no more than 16 colors. Their specific number depends on the palette used. The more of them, the better the image and you can see all the small details on it. In almost all palettes, the hottest objects are displayed in orange, yellow and red, and the coldest places are painted in blue or purple. There are also many other palettes. All of them are effective only in certain cases, which require the user to select the correct option before starting to survey the area.
The most popular palettes used in thermal imaging equipment are:
- White Hot. This palette is used quite often. It creates a picture that displays only white and black, as well as its shades. The first is used to display the hottest spots, and the second – the coldest. White Hot is widely used in monitoring objects located among buildings and various urban infrastructure. Also, this palette can be used in open areas, which are characterized by a sharp change in landscape.
- Black hot. This palette is in demand, as it makes it possible to obtain detailed images of good quality. It is widely used in thermal imaging sights, which are designed to perform various tasks by the military. This palette is also used to identify objects that look blurry in other palettes.
- Sepia. This palette is an improved version of White Hot. It allows you to create a two-tone image in warmer tones, which reduce the negative impact on the eyes and maximize user comfort. This makes the palette perfect for applications where thermal imagers are used for extended periods of time (during reconnaissance and similar operations).
- Ironbow. This palette does a great job of showing the distribution of heat. It makes it possible to examine in detail the degree of heating of even very small objects, which makes it one of the most popular among users. In Ironbow, cold spots are shown in dark colors (eg dark blue) and hot spots in light colors (eg light yellow). All this makes it possible to use the palette to obtain data on the degree of heating of individual parts of the human or animal body.
- 5 Rainbow. This palette is one of the most popular. It includes a large number of shades, thanks to which the user can see any changes in the degree of heating of the object. In addition, Rainbow is effective in conditions of minimal contrast. All these qualities make the palette in demand in the military and security spheres, as well as during search and rescue operations.
- Arctic. This palette is a combination of Rainbow and Ironbow. It is great for enhancing contrast, as it involves juxtaposing opposing hues (like yellow and purple) close to each other. Due to this feature, Arctic is used to view objects that are at a short distance from the user.
- Outdoor alert. This palette is designed to produce instant thermal images of people and animals. It is perfect for night time and effectively copes with its task even in conditions of maximum contrast. The basis of Outdoor alert are warm colors and shades. Most often, bright yellow, bright orange and other similar colors are used on an image with such a palette.
In addition to classic palettes, you can also use your own. This is easy to do, but for this you need to study some of the features of this process. The finished palette can include almost any number of shades that will correspond to certain temperature indicators. In some cases, there are also combined palette options, but this option is rarely used.
When using thermal imaging equipment, you should choose the right temperature base. Otherwise, the shades in the image will not be displayed with maximum accuracy. When setting, you must specify the lower and upper temperature values. They are set in accordance with generally accepted standards or are selected individually and depend on the tasks assigned to the user. In most cases, the default settings are sufficient. With them, it is possible to obtain a high-quality color display sufficient to find the features of the object in question. A slight adjustment of the base is also allowed. It is selected experimentally and its goal is to create the most detailed image with the ability to see minor temperature differences.
Another important parameter of thermal imaging equipment that affects the quality of color display is the temperature range. It is set depending on the number of shades used on the heat map. Each such shade corresponds to one or another temperature indicator, which makes it possible to quickly find out data on the degree of heating of the object in question. To obtain a high-quality picture, a range of 0.5 ° C will be sufficient. If you reduce this value by another 2-2.5 times, then detailing will suffer, but the quality will only increase. Extending the standard range will result in partial blurring, making object identification more difficult. This will make it possible to cover more heat sources. The choice of one of the described options depends on the nature of the task and the operating conditions of the thermal imager.
Thermal imaging optics is actively used in various fields of activity. It helps to find warm-blooded objects in the dark (for example, people or animals), as well as to find out the temperature of heated objects. Before you buy and use such devices, you need to learn in advance how to decipher the information received. To do this, study the features of the thermal image and the values of all its shades. These data will provide an opportunity to get a complete picture of the observed object, its characteristics and features.