Thermal infrared images of a scene are often useful for monitoring, inspection, and maintenance purposes. Often a thermal imaging device is provided to capture infrared information or data values indicative of the intensity of infrared energy received from the scene, and create or generate a visual representation of the captured infrared information. For example, infrared information may be presented in the form of an infrared image, which represents infrared radiation emitted from an observed real world scene.
Infrared radiation is not visible to the human eye; there are no natural relations between the captured infrared image data values of each pixel in an infrared image and colors of a visual representation of the infrared image generated on a display. Therefore, information visualization processes, often referred to as false coloring or pseudo-coloring, are typically used to map captured infrared image data value of each pixel in an infrared image to a corresponding color or grayscale displayed on a display according to a palette or look-up table (LUT).
Color used to depict thermal images is useful because it stimulates a perceived contrast response in the brain that exceeds the perceived contrast between gray levels. Traditional color palettes or LUTs are designed around colors of the rainbow, the colors of incandescent objects at different temperatures, or other aesthetically appealing color arrangements, and typically map infrared image data values to a limited number of output color levels (e.g., 8-bit, or 256, color levels).
The perceived color contrast in the aforementioned examples is low between adjacent 8-bit output color levels resulting in difficulty distinguishing consecutive temperatures of the captured image. As a result, there is a need for improved techniques for visualization of local areas of interest in a displayed infrared image, particularly in regards to infrared imaging color palettes.