| 摘要 |
PURPOSE:To provide the target extracting device for extracting a gradation image corresponding to the shape of a desired target while being hardly affected by the distribution of the density value of a background. CONSTITUTION:When the gradation image is inputted to a geometrical feature amount measuring circuit 1 and a threshold value is calculated for each density value, the geometrical feature amount in the area of a binary image provided by each threshold value is measured. The geometrical feature amount of the shape of the desired target to be extracted is previously stored in a target feature amount storage circuit 2, and a feature amount comparative arithmetic circuit 3 calculates the comparatively calculated result for each density by comparing the geometrical feature amount for each density value measured by the geometrical feature amount measuring circuit 1 with the feature amount of the shape of the target from the target feature amount storage circuit 2 and calculates a threshold value for binarizing by inputting the comparatively calculated result for each density value to a threshold value calculation circuit 4. Then, the target is extracted by inputting the calculated threshold value to a binary image generating circuit 5. |
