ありがとうございました。
ただ一つのことhttps://math.stackexchange.com/a/339033] [私はあなたのリンクをたどると、私は私が欲しいものを見つける、私はピクセル関連L < -R
を見つけるために、C行列を反転させる必要があり、私はのアイデアを与えるために私のコードを共有しますあなたはあなたが機能computeMat（で私の実装を見つけることができます しなければならない）
<style>
body {
touch-action: none;
overflow-y: hidden;
}
#canvas_toeic
{
position:absolute;
top:0;
left:0;
}
</style>
<script type="text/javascript" src="http://cdnjs.cloudflare.com/ajax/libs/mathjs/3.12.2/math.min.js"></script>
</head>
<body>
<canvas id="canvas_toeic" width="600" height="400">
</canvas>
<script type="text/javascript">
var image = new Image();
image.src = 'image.jpg';
image.onload = function() {
var c = document.getElementById("canvas_toeic");
var ratio = image.width/image.height;
var canvasWidth = document.body.clientWidth;
var canvasHeight = canvasWidth/ratio;
if(document.body.clientHeight < canvasHeight)
{
canvasHeight = document.body.clientHeight;
canvasWidth = canvasHeight * ratio;
}
var canvasLargeur = canvasWidth;
var canvasLongueur = canvasHeight;
if(canvasLargeur < canvasHeight) {
canvasLargeur = canvasHeight;
canvasLongueur = canvasWidth;
}
var canvasPixelRatio = canvasLargeur/image.width;
c.setAttribute("width", canvasWidth);
c.setAttribute("height", canvasHeight);
var ctx = c.getContext("2d");
var idPoint = -1;
var points = [];
for(var i = 0; i < 4; i++)
points[i] = {x:0, y:0};
var marginImage = Math.round(40 * canvasPixelRatio);
points[0].x = marginImage;
points[0].y = marginImage;
points[1].x = marginImage;
points[1].y = canvasHeight - marginImage;
points[2].x = canvasWidth - marginImage;
points[2].y = canvasHeight - marginImage;
points[3].x = canvasWidth - marginImage;
points[3].y = marginImage;
function draw(points) {
console.log("draw");
// Fond
ctx.fillStyle = "#222";
ctx.fillRect(0, 0, canvasWidth, canvasHeight);
ctx.drawImage(image, marginImage, marginImage, canvasWidth - marginImage * 2, canvasHeight - marginImage * 2); // this fait référence à l'objet courant (=image)
if(idPoint == -1)
ctx.lineWidth = 3 * canvasPixelRatio;
else
ctx.lineWidth = 5 * canvasPixelRatio;
ctx.beginPath(); // Début du chemin
ctx.lineJoin = "round";
ctx.lineCap = "round";
ctx.strokeStyle = "rgba(64, 128, 255, 0.5)";
ctx.moveTo(points[0].x, points[0].y); // Le tracé part du point 50,50
for(var i = 0; i < 4; i++)
ctx.lineTo(points[i].x, points[i].y); // Un segment est ajouté vers 200,200
ctx.closePath(); // Fermeture du chemin (facultative)
ctx.stroke();
for(var i = 0; i < 4; i++)
{
var radius = 30 * canvasPixelRatio;
if(idPoint == i)
radius = 60 * canvasPixelRatio;
ctx.beginPath();
ctx.arc(points[i].x, points[i].y, radius, 0, Math.PI*2, true);
ctx.strokeStyle = "#FF8800";
ctx.fillStyle = "rgba(255, 128, 0, 0.5)";
ctx.fill();
ctx.stroke();
}
if(idPoint != -1)
{
var zoomWidth = canvasWidth/3;
var zoomHeight = canvasHeight/3;
var zoomMargin = 5;
var zoomAroundWidth = 50;
var zoomAroundHeight = zoomAroundWidth/ratio;
var positionMouse = points[idPoint];
var imagePositionX = (positionMouse.x - marginImage)/(canvasWidth - marginImage * 2) * image.width;
var imagePositionY = (positionMouse.y - marginImage)/(canvasHeight - marginImage * 2) * image.height;
var zoomX = 0;
var zoomY = 0;
if(imagePositionX < image.width/2)
zoomX = canvasWidth - zoomWidth;
if(imagePositionY < image.height/2)
zoomY = canvasHeight - zoomHeight;
ctx.fillStyle = "#F08";
ctx.fillRect(zoomX, zoomY, zoomWidth, zoomHeight);
ctx.drawImage(image, imagePositionX - zoomAroundWidth, imagePositionY - zoomAroundHeight, zoomAroundWidth * 2, zoomAroundHeight * 2, zoomX + zoomMargin, zoomY + zoomMargin, zoomWidth - zoomMargin * 2, zoomHeight - zoomMargin * 2);
ctx.lineWidth = 3 * canvasPixelRatio;
ctx.beginPath();
ctx.lineJoin = "round";
ctx.lineCap = "round";
ctx.strokeStyle = "rgba(255, 0, 0, 0.5)";
ctx.moveTo(zoomX, zoomY + zoomHeight/2);
ctx.lineTo(zoomX + zoomWidth, zoomY + zoomHeight/2);
ctx.moveTo(zoomX + zoomWidth/2, zoomY);
ctx.lineTo(zoomX + zoomWidth/2, zoomY + zoomHeight);
ctx.closePath();
ctx.stroke();
}
}
function nearPoint(points, x, y)
{
var radiusDetection = 60 * canvasPixelRatio;
var distances = [];
for(i = 0; i < 4; i++) {
var mx = x - points[i].x;
var my = y - points[i].y;
distances[i] = Math.sqrt(mx * mx + my * my);
}
minI = 0;
minD = distances[0];
for(i = 1; i < 4; i++)
{
if(minD > distances[i])
{
minD = distances[i];
minI = i;
}
}
if(minD <= radiusDetection)
return minI;
return -1;
}
function getTouchPosition(e)
{
var target = null;
var mouse = null;
if(e.changedTouches != undefined)
{
var touches = e.changedTouches;
mouse = touches[0];
target = touches[0].target;
}
else if(e.originalTarget != undefined)
{
mouse = e;
target = e.originalTarget;
}
var coordX = 0;
var coordY = 0;
if(mouse.layerX != undefined)
{
coordX = mouse.layerX;
coordY = mouse.layerY;
}
else
{
coordX = mouse.pageX;
coordY = mouse.pageY;
}
var x = coordX - target.offsetLeft;
var y = coordY - target.offsetTop;
if(x < 0) x = 0;
if(y < 0) y = 0;
if(x >= canvasWidth) x = canvasWidth - 1;
if(y >= canvasHeight) y = canvasHeight - 1;
return {'x':x, 'y':y};
}
function mouseDown(e)
{
var position = getTouchPosition(e);
idPoint = nearPoint(points, position.x, position.y);
if(idPoint == -1)
{
if(position.x < marginImage * 3 && position.y < marginImage * 3)
{
computeMat();
}
}
}
function mouseUp(e)
{
if(idPoint != -1)
{
idPoint = -1;
draw(points);
}
}
function mouseMove(e)
{
if(idPoint != -1)
{
var position = getTouchPosition(e);
points[idPoint].x = position.x;
points[idPoint].y = position.y;
draw(points);
}
}
function cancelDefault(e)
{
e.preventDefault();
}
function matStep12(pts)
{
var matP = [
[pts[0].x, pts[1].x, pts[2].x],
[pts[0].y, pts[1].y, pts[2].y],
[1, 1, 1]
];
var vecP = [[pts[3].x], [pts[3].y], [1]];
var matPi = math.inv(matP);
var vecPi = math.multiply(matPi, vecP);
var result = [
[pts[0].x * vecPi[0][0], pts[1].x * vecPi[1][0], pts[2].x * vecPi[2][0]],
[pts[0].y * vecPi[0][0], pts[1].y * vecPi[1][0], pts[2].y * vecPi[2][0]],
[vecPi[0][0], vecPi[1][0], vecPi[2][0]]
];
return result;
}
function distance(a, b)
{
var mx = b.x - a.x;
var my = b.y - a.y;
return Math.sqrt(mx * mx + my * my);
}
function computeMat()
{
var pts = getPointRelativePosition();
var widthT = distance(pts[0], pts[3]);
var widthB = distance(pts[1], pts[2]);
var heightL = distance(pts[0], pts[1]);
var heightR = distance(pts[2], pts[3]);
var maxWidth = (widthT > widthB) ? widthT : widthB;
var maxHeight = (heightL > heightR) ? heightL : heightR;
var imgWidth = Math.round(maxWidth);
var imgHeight = Math.round(maxHeight);
var matA = matStep12(pts);
var matB = matStep12([{x:0,y:0}, {x:0,y:maxHeight}, {x:maxWidth,y:maxHeight}, {x:maxWidth,y:0}]);
var matC = math.multiply(matB, math.inv(matA));
var matCi = math.inv(matC);
console.log('width:' + imgWidth + ', height:' + imgHeight);
printMat(matC);
// construct image with transformation matrice
imageData = ctx.createImageData(imgWidth, imgHeight);
var tempCanvas = document.createElement('canvas');
var tempCtx = tempCanvas.getContext('2d');
tempCanvas.width = image.width;
tempCanvas.height = image.height;
tempCtx.drawImage(image, 0, 0, image.width, image.height);
var imageDataSrc = tempCtx.getImageData(0, 0, image.width, image.height);
var mz = [matCi[0][2], matCi[1][2], matCi[2][2]];
for(var y = 0; y < imgHeight; y++)
{
var my = [matCi[0][1] * y, matCi[1][1] * y, matCi[2][1] * y];
var offsetY = y * imgWidth;
for(var x = 0; x < imgWidth; x++)
{
var mx = [matCi[0][0] * x, matCi[1][0] * x, matCi[2][0] * x];
var cx = mx[0] + my[0] + mz[0];
var cy = mx[1] + my[1] + mz[1];
var cz = mx[2] + my[2] + mz[2];
var px = Math.round(cx/cz);
var py = Math.round(cy/cz);
if(px < 0.0 || py < 0.0 || px >= image.width || py >= image.height)
{
imageData.data[pixelIndex] = 0;
imageData.data[pixelIndex + 1] = 255;
imageData.data[pixelIndex + 2] = 0;
imageData.data[pixelIndex + 3] = 255;
}
else
{
var pixelIndex = (offsetY + x) * 4;
var pixelIndexSrc = (py * image.width + px) * 4;
imageData.data[pixelIndex] = imageDataSrc.data[pixelIndexSrc];
imageData.data[pixelIndex + 1] = imageDataSrc.data[pixelIndexSrc + 1];
imageData.data[pixelIndex + 2] = imageDataSrc.data[pixelIndexSrc + 2];
imageData.data[pixelIndex + 3] = 255;
}
}
}
// here to do, image analysis
}
function getPointRelativePosition()
{
var pointOrigin = [];
for(i = 0; i < 4; i++)
{
pointOrigin[i] = {x:(points[i].x - marginImage) * image.width/(canvasWidth - marginImage * 2), y:(points[i].y - marginImage) * image.height/(canvasHeight - marginImage * 2)};
}
return pointOrigin;
}
function getPointPosition()
{
var pointOrigin = [];
for(i = 0; i < 4; i++)
{
pointOrigin[i] = {x:(points[i].x - marginImage)/(canvasWidth - marginImage * 2), y:(points[i].y - marginImage)/(canvasHeight - marginImage * 2)};
}
return pointOrigin;
}
function printPoint(pts)
{
var result = '';
for(var i = 0; i < 4; i++)
{
result += "{x:" + pts[i].x + ", y:" + pts[i].y + "},\n";
}
console.log(result);
}
function printMat(mat)
{
var result = '';
for(var i = 0; i < mat.length; i++)
{
result += "[";
for(var j = 0; j < mat[i].length; j++)
{
result += mat[i][j] + ", ";
}
result += "],\n";
}
console.log(result);
}
function canvasResize()
{
if(canvasWidth != document.body.clientWidth && canvasHeight != document.body.clientHeight)
{
var transformPoint = getPointPosition();
ratio = image.width/image.height;
canvasWidth = document.body.clientWidth;
canvasHeight = canvasWidth/ratio;
if(document.body.clientHeight < canvasHeight)
{
canvasHeight = document.body.clientHeight;
canvasWidth = canvasHeight * ratio;
}
canvasLargeur = canvasWidth;
canvasLongueur = canvasHeight;
if(canvasLargeur < canvasHeight) {
canvasLargeur = canvasHeight;
canvasLongueur = canvasWidth;
}
canvasPixelRatio = canvasLargeur/image.width;
c.setAttribute("width", canvasWidth);
c.setAttribute("height", canvasHeight);
marginImage = Math.round(40 * canvasPixelRatio);
for(i = 0; i < 4; i++)
{
points[i].x = transformPoint[i].x * (canvasWidth - marginImage * 2) + marginImage;
points[i].y = transformPoint[i].y * (canvasHeight - marginImage * 2) + marginImage;
}
draw(points);
}
}
c.addEventListener("mousedown", mouseDown, false);
c.addEventListener("mouseup", mouseUp, false);
c.addEventListener("mousemove", mouseMove, false);
c.addEventListener("touchstart", mouseDown, false);
c.addEventListener("touchend", mouseUp, false);
c.addEventListener("touchmove", mouseMove, false);
document.addEventListener("touchstart", cancelDefault, true);
document.addEventListener("touchend", cancelDefault, true);
document.addEventListener("touchmove", cancelDefault, true);
setInterval(canvasResize, 30);
draw(points);
};
</script>
この行列は、直接変換L-> Rまたは後の1つのR-> Lの行列ですか？ 2D変換で行列が3x3ではなく4x4になるのはなぜですか？シフトコンポーネント（12/-17？）が小さすぎます。 – MBo
相互参照：4点とその画像が与えられた行列を見つける手順については、https://math.stackexchange.com/a/339033/35416を参照してください。答えとコメントには、JavaScript/CSSデモが動作しています。 – MvG