Ground Truth

In digital imaging and OCR, ground truth is the objective verification of the particular properties of a digital image, used to test the accuracy of automated image analysis processes. The ground truth of an image’s text content, for instance, is the complete and accurate record of every character and word in the image. This can be compared to the output of an OCR engine
and used to assess the engine’s accuracy, and how important any deviation from ground truth is in that instance.