Uncaught TypeError: changePerspective is not a function const changePerspective = require('change-perspective'); const srcCorners = [158, 64, 494, 69, 495, 404, 158, 404]; const dstCorners = [100, 500, 152, 564, 148, 604, 100, 560]; const transform = changePerspective(srcCorners, dstCorners); const srcPt = [250, 120]; const dstPt = transform(srcPt[0], srcPt[1]); going to use https://github.com/jlouthan/perspective-transform instead