位平面和SIFT相结合的图像匹配方法

针对传统的相关匹配算法计算量大，对图像旋转敏感等问题，提出了一种位平面和尺度不变特征变换（SIFT）相结合的图像匹配算法。将待拼接的两幅图像A、]B]各自分解为8个位平面，对两幅图像都选择前4个具有视觉信息的位平面A1A2A3A4]和B1B2B3B4]；对A1A2、]A2A3、]A3A4]图像进行异或运算，得到3幅图像。由于异或后的图像A1A2]具有足够的细节部分，轮廓却不清晰，图像A3A4]轮廓清晰，但是丢失了太多细节，而图像A2A3]具有清晰的轮廓，又具有足够的细节信息，所以采用图像A2A3]，然后与原图像A]进行异或得到A]，同时采用同样的方法得到图像B]，再次采用SIFT算法进行点对匹配，利用欧氏距离进行图像匹配，最后利用RANSAC进行图像容错处理，得到一幅匹配图像。实验结果表明，该算法有效地提高了匹配速度，对图像明暗变化、尺度旋转等具有较强的健壮性。

Image matching algorithm based on combination of bit planes and SIFT

Traditional-correlation-based matching methods require heavy computation time and they are sensitive to image rotation. This paper presents an image matching algorithm by combining bit planes and SIFT. It divides the two spliced imagesA]andB]into eight bit planes. The top four bit planes with visual informationA1A2A3A4]andB1B2B3B4]are selected from the two images. Then, using the imagesA1A2,]A2A3]andA3A4]to XOR, it gets three images. Since after XOR, the imageA1A2]gets many details, but the contour is not clear;while the imageA3A4]has clear contour, but losts too many details; the imageA2A3]has clear contour, and also has enough detail information. So the paper selects the imageA2A3,]then uses imageA2A3]and the originalA]to XOR, and gets the imageA,]at the same time, uses the same method to get the imageB,]and SIFT algorithm to match again. Euclidean distance is used for image matching. Finally the RANSAC is used to process fault-tolerant, and gets a matching image. The experimental results show that the algorithm can effectively improve the matching speed, the image brightness changes, rotation and scale, with strong robustness.