| 摘要 |
In connection with a method of interpreting thermographic data for nondestructive evaluation of subsurface structural irregularities in a sample object, the sample object is thermally excited and then allowed to cool. As the thermal energy level on the object's surface changes, a series of positionally-fixed infrared images of the object are acquired. The method calculates a pixel sum set for each image in the series by counting the number of pixels in each image which display each of the different pixel shades of gray (or colors). The mathematical moments of each of the functions derived from the pixel sum sets are then calculated, producing a single total energy value for each image, the total energy values collectively being referred to as a total energy value set. The total energy value set acquired from the sample object is compared to a control total energy value set expected from an infinitely thick, perfectly homogenous object to identify anomalous surface infrared radiation patterns, indicating subsurface structural irregularities in the sample object. Alternatively, instead of taking the mathematical moment of the pixel sum sets, the pixel sum sets themselves may be compared individually to a control pixel sum set expected from an infinitely thick, perfectly homogenous object, likewise identifying anomalous surface infrared radiation patterns.
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