Add sample data, modify paths accordingly.

[avisingh599]

[sunnyHelen]

Hi, I wanna ask what dataset you use in kitti, color,grey orvelodyne laser data. I hope add some data to use your code. But I don't know use what kind of data to use your code. I just start to learn slam recently with very little experience. Can you tell me? Thank you very much.

[BJMH]

The code works with the colour KITTI odometry data set. However, the call to cvtColor(img_1_c, img_1, COLOR_BGR2GRAY); converts it to grey scale, so it would probably run the same on the grey scale data set.

If you change the strings that load the images, it should work with any colour or grey scale sequence of images supported by cv::imread(). However, I tried it on the New Tsukuba data set and got very poor results, whilst it works amazingly on the KITTI data set.