Filtering-based error-tolerability evaluation of image processing circuits

For some systems errors can be regarded as being acceptable as long as their significance is low enough. Image processing circuits are one such example due to human being´s insensitivity to minor errors in colors. Significant errors usually destroy the structure of an image, and thus appear to be perceptible. This also makes larger changes to the frequency feature of the image. By examining the degree at which the frequency is varied, the acceptability of errors can be determined. In this work we propose a filtering-based test method that can quantify the frequency variance incurred by errors. According to the obtained variance value, the acceptability of an image can be determined by comparing the value with user-specified thresholds. The experimental results on a large number of erroneous benchmark images show that the proposed method can accurately differentiate unacceptable images from acceptable ones. The implementation of the proposed method is simple, and thus can facilitate implementation of a BIST (Built-In Self-Test) circuitry for efficient product grading, as well as in-field reliability determination and enhancement. This is useful when the target circuit is employed in some critical applications such as automotive or medical electronic systems.