| 摘要 |
<p>A device is proposed for automatic analysis of digital grayscale images of objects under test to detect foreign bodies or other specific regions darker than background. The proposed analyzer removes the alternating image background from the input pixels' data (8) using the digital filter (1), calculates coefficients characterizing covariance between pixel values of small groups of r x r pixels in r lines of the filtered image and generates the alarm signal (18) if any value of such coefficient exceeds some practically chosen level (14). Besides of the digital filter (1) mentioned above, analyzer contains r-1 FIFO memories (2) connected in series and r groups of registers (3) with r registers in every group for storing values of the filtered image pixels, arithmetic unit (4) for calculating of coefficients (13) mentioned above, code comparator (5) for comparison of calculated coefficients (13) with the chosen threshold (14) and generating primary alarm signal (15), and the alarm unit (6), generating alarm output signal (18), which is acknowledged by an external signal (17). All internal units of this analyzer are clocked by the pixel clock signal (7) and line clock signal (16), pixel codes from filter's (1) output (9) are shipped to input of the 1st register (3) of the 1st registers' group and to the input of the 1st memory (2), all outputs (10) of memories (2) are connected to inputs of other registers (3) of the 1st register group, all outputs (11) of the 1st registers' group are connected to inputs of the next registers' group and to inputs of the arithmetical unit (4), outputs (12) of the last registers' group are connected only to inputs the of arithmetical unit (4). The proposed analyzer is suitable for real-time image analysis systems, can be implemented on the basis of programmable electronic devices with low energy consumption and used in various industrial and medical systems.</p> |
