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| "use strict";
|
| module.exports = function paethPredictor(left, above, upLeft) {
| let paeth = left + above - upLeft;
| let pLeft = Math.abs(paeth - left);
| let pAbove = Math.abs(paeth - above);
| let pUpLeft = Math.abs(paeth - upLeft);
|
| if (pLeft <= pAbove && pLeft <= pUpLeft) {
| return left;
| }
| if (pAbove <= pUpLeft) {
| return above;
| }
| return upLeft;
| };
|
|