konva/lib/filters/Mask.js

HTML5 2d canvas library.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Mask = void 0;
const Factory_1 = require("../Factory");
const Node_1 = require("../Node");
const Validators_1 = require("../Validators");
function pixelAt(idata, x, y) {
    let idx = (y * idata.width + x) * 4;
    const d = [];
    d.push(idata.data[idx++], idata.data[idx++], idata.data[idx++], idata.data[idx++]);
    return d;
}
function rgbDistance(p1, p2) {
    return Math.sqrt(Math.pow(p1[0] - p2[0], 2) +
        Math.pow(p1[1] - p2[1], 2) +
        Math.pow(p1[2] - p2[2], 2));
}
function rgbMean(pTab) {
    const m = [0, 0, 0];
    for (let i = 0; i < pTab.length; i++) {
        m[0] += pTab[i][0];
        m[1] += pTab[i][1];
        m[2] += pTab[i][2];
    }
    m[0] /= pTab.length;
    m[1] /= pTab.length;
    m[2] /= pTab.length;
    return m;
}
function backgroundMask(idata, threshold) {
    const rgbv_no = pixelAt(idata, 0, 0);
    const rgbv_ne = pixelAt(idata, idata.width - 1, 0);
    const rgbv_so = pixelAt(idata, 0, idata.height - 1);
    const rgbv_se = pixelAt(idata, idata.width - 1, idata.height - 1);
    const thres = threshold || 10;
    if (rgbDistance(rgbv_no, rgbv_ne) < thres &&
        rgbDistance(rgbv_ne, rgbv_se) < thres &&
        rgbDistance(rgbv_se, rgbv_so) < thres &&
        rgbDistance(rgbv_so, rgbv_no) < thres) {
        const mean = rgbMean([rgbv_ne, rgbv_no, rgbv_se, rgbv_so]);
        const mask = [];
        for (let i = 0; i < idata.width * idata.height; i++) {
            const d = rgbDistance(mean, [
                idata.data[i * 4],
                idata.data[i * 4 + 1],
                idata.data[i * 4 + 2],
            ]);
            mask[i] = d < thres ? 0 : 255;
        }
        return mask;
    }
}
function applyMask(idata, mask) {
    for (let i = 0; i < idata.width * idata.height; i++) {
        idata.data[4 * i + 3] = mask[i];
    }
}
function erodeMask(mask, sw, sh) {
    const weights = [1, 1, 1, 1, 0, 1, 1, 1, 1];
    const side = Math.round(Math.sqrt(weights.length));
    const halfSide = Math.floor(side / 2);
    const maskResult = [];
    for (let y = 0; y < sh; y++) {
        for (let x = 0; x < sw; x++) {
            const so = y * sw + x;
            let a = 0;
            for (let cy = 0; cy < side; cy++) {
                for (let cx = 0; cx < side; cx++) {
                    const scy = y + cy - halfSide;
                    const scx = x + cx - halfSide;
                    if (scy >= 0 && scy < sh && scx >= 0 && scx < sw) {
                        const srcOff = scy * sw + scx;
                        const wt = weights[cy * side + cx];
                        a += mask[srcOff] * wt;
                    }
                }
            }
            maskResult[so] = a === 255 * 8 ? 255 : 0;
        }
    }
    return maskResult;
}
function dilateMask(mask, sw, sh) {
    const weights = [1, 1, 1, 1, 1, 1, 1, 1, 1];
    const side = Math.round(Math.sqrt(weights.length));
    const halfSide = Math.floor(side / 2);
    const maskResult = [];
    for (let y = 0; y < sh; y++) {
        for (let x = 0; x < sw; x++) {
            const so = y * sw + x;
            let a = 0;
            for (let cy = 0; cy < side; cy++) {
                for (let cx = 0; cx < side; cx++) {
                    const scy = y + cy - halfSide;
                    const scx = x + cx - halfSide;
                    if (scy >= 0 && scy < sh && scx >= 0 && scx < sw) {
                        const srcOff = scy * sw + scx;
                        const wt = weights[cy * side + cx];
                        a += mask[srcOff] * wt;
                    }
                }
            }
            maskResult[so] = a >= 255 * 4 ? 255 : 0;
        }
    }
    return maskResult;
}
function smoothEdgeMask(mask, sw, sh) {
    const weights = [1 / 9, 1 / 9, 1 / 9, 1 / 9, 1 / 9, 1 / 9, 1 / 9, 1 / 9, 1 / 9];
    const side = Math.round(Math.sqrt(weights.length));
    const halfSide = Math.floor(side / 2);
    const maskResult = [];
    for (let y = 0; y < sh; y++) {
        for (let x = 0; x < sw; x++) {
            const so = y * sw + x;
            let a = 0;
            for (let cy = 0; cy < side; cy++) {
                for (let cx = 0; cx < side; cx++) {
                    const scy = y + cy - halfSide;
                    const scx = x + cx - halfSide;
                    if (scy >= 0 && scy < sh && scx >= 0 && scx < sw) {
                        const srcOff = scy * sw + scx;
                        const wt = weights[cy * side + cx];
                        a += mask[srcOff] * wt;
                    }
                }
            }
            maskResult[so] = a;
        }
    }
    return maskResult;
}
const Mask = function (imageData) {
    const threshold = this.threshold();
    let mask = backgroundMask(imageData, threshold);
    if (mask) {
        mask = erodeMask(mask, imageData.width, imageData.height);
        mask = dilateMask(mask, imageData.width, imageData.height);
        mask = smoothEdgeMask(mask, imageData.width, imageData.height);
        applyMask(imageData, mask);
    }
    return imageData;
};
exports.Mask = Mask;
Factory_1.Factory.addGetterSetter(Node_1.Node, 'threshold', 0, (0, Validators_1.getNumberValidator)(), Factory_1.Factory.afterSetFilter);