andrew
/
xwordjs


			
				
					
						
						
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							<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
        <script src="js/vendor/opencv/opencv.js"></script>
        <script src="js/vendor/interact/interact.min.js"></script>
        <script src="js/vendor/load-image/load-image.all.min.js"></script>
        <script src="js/vendor/moment/moment.min.js"></script>
        <script src="js/xword.js"></script>
        <style>
            #sourceImageContainer {
                width: 100%;
                overflow: scroll;
                touch-action: pan-x pan-y;
            }
            #sourceImage {
                position: relative;
            }
            #sourceImage .overlay {
                position: absolute;
                left: 0;
                top: 0;
            }
            .handle {
                position: absolute;
                box-sizing: border-box;
                width: 71px;
                height: 71px;
                border-radius: 50%;
                border: 2px solid red;
                transform: translate(-50%, -50%);
                touch-action: none;
            }
            #outputContainer {
                width: 100%;
            }
            canvas {
                width: 100%;
            }
        </style>
    </head>
    <body>
        <div>
            <input type="file" id="fileInput">
        </div>
        <div id="sourceImageContainer">
            <div id="sourceImage"></div>
        </div>
        <button id="recalculateButton">Recalculate</button>
        <div id="outputContainer">
            <canvas id="output"></canvas>
        </div>
        <div>
            <a id="download" href="#" download="crossword.png">Download</a>
        </div>
        <script>
            'use strict';

            let sourceImage = document.getElementById("sourceImage");
            let sourceImageParent = sourceImage.parentElement;
            let fileInput = document.getElementById("fileInput");
            let output = document.getElementById('output');
            let downloadLink = document.getElementById('download');
            let recalculateButton = document.getElementById('recalculateButton');

            let isSquare = true;

            let gaussianBlurSize = 11;
            let adaptiveThresholdBlockSize = 11;
            let adaptiveThresholdMeanAdjustment = 2;
            let numDilations = 1;

            let contourErosionKernelSize = 5;
            let contourErosionIterations = 5;

            let lineDetectorElementSize = 51;

            let samplingBlockSizeRatio = 0.25;

            let gridLineThickness = 4;
            let gridSquareInternalSize = 64;
            let gridMarginSize = 20;

            let src = null;
            let img = null;

            let wheelCallback = null;
            let gestureCallback = null;

            sourceImageParent.addEventListener('wheel', function(event) {
                if (wheelCallback != null) {
                    wheelCallback(event);
                }
            });

            interact(sourceImageParent).gesturable({
                onmove: function(event) {
                    if (gestureCallback != null) {
                        gestureCallback(event);
                    }
                }
            });

            fileInput.onchange = function(e) {
                if (e.target.files.length > 0) {
                    loadImage(
                        e.target.files[0],
                        function(canvas) {
                            let imageWidth = canvas.width;
                            let imageHeight = canvas.height;
                            let containerWidth = sourceImageParent.offsetWidth;
                            let scaledWidth = containerWidth;
                            sourceImageParent.style.height = Math.round(imageHeight * scaledWidth / imageWidth) + 'px';

                            if (src != null) {
                                src.delete();
                                src = null;
                            }

                            if (img != null) {
                                img.delete();
                                img = null;
                            }

                            while (sourceImage.firstChild) {
                                sourceImage.removeChild(sourceImage.firstChild);
                            }
                            sourceImage.appendChild(canvas);

                            let overlay = document.createElement('canvas');
                            overlay.className = 'overlay';
                            overlay.width = imageWidth;
                            overlay.height = imageHeight;
                            sourceImage.appendChild(overlay);

                            let context = overlay.getContext('2d');
                            context.globalAlpha = 0.6;
                            context.strokeStyle = 'red';

                            let handles = [];

                            function getCornersFromHandles() {
                                let corners = [];
                                handles.forEach(function(handle) {
                                    corners.push(new cv.Point(
                                        parseFloat(handle.dataset.left),
                                        parseFloat(handle.dataset.top)
                                    ));
                                });
                                return corners;
                            }

                            function redrawOverlay() {
                                let corners = getCornersFromHandles();
                                context.lineWidth = imageWidth / scaledWidth;
                                context.clearRect(0, 0, imageWidth, imageHeight);
                                context.beginPath();
                                let corner = corners[corners.length - 1];
                                context.moveTo(corner.x, corner.y);
                                corners.forEach(function(corner) {
                                    context.lineTo(corner.x, corner.y);
                                });
                                context.stroke();
                            }

                            function resize() {
                                sourceImage.style.width = scaledWidth + 'px';
                                redrawOverlay();
                            }

                            function repositionHandle(handle) {
                                handle.style.left = (parseFloat(handle.dataset.left) / imageWidth * 100) + '%';
                                handle.style.top = (parseFloat(handle.dataset.top) / imageHeight * 100) + '%';
                            }

                            function dragMoveListener(event) {
                                let target = event.target;
                                let scale = scaledWidth / imageWidth;
                                target.dataset.left = Math.min(
                                    imageWidth - 1,
                                    Math.max(0, parseFloat(target.dataset.left) + event.dx / scale)
                                );
                                target.dataset.top = Math.min(
                                    imageHeight - 1,
                                    Math.max(0, parseFloat(target.dataset.top) + event.dy / scale)
                                );
                                repositionHandle(target);
                                redrawOverlay();
                            }

                            function recalculate() {
                                let numRows;
                                let numCols;
                                let corners = getCornersFromHandles();
                                let square = extractSquare(img, corners);
                                try {
                                    numRows = getLineFrequency(square, lineDetectorElementSize, 1);
                                    numCols = getLineFrequency(square, lineDetectorElementSize, 0);
                                    if (isSquare && (numRows !== numCols)) {
                                        console.log("WARNING: crossword is not square");
                                    }
                                } finally {
                                    square.delete();
                                }

                                let blockImg = extractSquare(src, corners);
                                let grid;
                                try {
                                    let gridColours = extractGridColours(blockImg, numRows, numCols, samplingBlockSizeRatio);
                                    let threshold = getGridColourThreshold(gridColours);
                                    grid = gridColoursToBlocks(gridColours, numRows, numCols, threshold);
                                } finally {
                                    blockImg.delete();
                                }

                                if (grid.warning) {
                                    console.log("WARNING: some blocks may be the wrong colour");
                                }
                                drawGrid(output, grid.blocks, numRows, numCols, gridLineThickness, gridSquareInternalSize, gridMarginSize);
                                downloadLink.href = output.toDataURL("image/png");
                                downloadLink.download = 'crossword_' + moment().format('YYYYMMDD_HHmmss') + '.png';
                            }

                            function zoomChanged(delta) {
                                scaledWidth = Math.min(
                                    imageWidth,
                                    Math.max(containerWidth, scaledWidth + delta)
                                );
                                resize();
                            }

                            recalculateButton.onclick = recalculate;
                            wheelCallback = function(event) {
                                if (! event.shiftKey) return;
                                event.preventDefault();
                                zoomChanged(-event.deltaY);
                            }
                            gestureCallback = function(event) {
                                zoomChanged(scaledWidth * event.ds);
                            }

                            src = cv.imread(canvas);

                            //removeColours(src, src, 48);
                            //cv.imshow('output', src);

                            cv.cvtColor(src, src, cv.COLOR_RGBA2GRAY, 0);

                            img = new cv.Mat();
                            preprocessImage(src, img, gaussianBlurSize, adaptiveThresholdBlockSize, adaptiveThresholdMeanAdjustment, numDilations);
                            //cv.imshow('output', img);
                            let corners;
                            let biggest = findBiggestContour(img);
                            try {
                                let eroded = erodeContour(img.size(), biggest, contourErosionKernelSize, contourErosionIterations);
                                try {
                                    corners = getContourCorners(img.size(), eroded);
                                } finally {
                                    eroded.delete();
                                }
                            } finally {
                                biggest.delete();
                            }

                            corners.forEach(function(corner) {
                                let handle = document.createElement('div');
                                handle.className = 'handle';
                                handle.dataset.left = corner.x;
                                handle.dataset.top = corner.y;
                                repositionHandle(handle);
                                sourceImage.appendChild(handle);
                                interact(handle).draggable({
                                    onmove: dragMoveListener
                                });
                                handles.push(handle);
                            });

                            resize();
                            recalculate();
                        },
                        {
                            orientation: true
                        }
                    );
                }
            };
        </script>
    </body>
</html>
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