Unexpected warping results

I've just created a module that allows me to generate a mapping function for ndarray-warp, to distort an image like imagemagick's shepard's distortion: https://github.com/ismay/generate-map

It allows you to specify a set of coordinates and their intended displacement, which results in images like these:

(warped with these parameters: [[210, 296, 100, 0], [101, 97, -30, -10], [77, 473, 50, -100]], see test here: https://github.com/ismay/generate-map/blob/master/lib/index.test.js)

Everything works as expected, but I encountered two things that I wasn't able to solve:

1. Output is rotated 90 degrees counterclockwise (also when just passing an image through ndarray-warp without doing anything). Seems like a bug? Or am I doing something wrong here?

2. Another thing that I noticed and could not figure out from this project's documentation is that the output is grayscale, even though the original image is in color. Is there anything I could do to output color images?

Thanks!

1. So point 1 is because the lena package returns a rotated version of the image: Lena is transposed mikolalysenko/lena#1. Using baboon-image returns an unrotated version of the image.

2. Using const outputImage = zeros([inputImage.shape[0], inputImage.shape[1], 3]); doesn't fix the lack of color. Even though it seems like this package should autodetect the dimensions used?

I moved the repo to https://github.com/ismay/ndarray-morph, and removed ndarray-warp, which fixed the problem (see this commit https://github.com/ismay/ndarray-morph/commit/9c7a39458ea765201fd554278caa3818e4060765). So for me the problem's fixed, but it might be good to address problem 2 for this lib.