oops, forgot to commit transform.js

geocamTiePoint/static/geocamTiePoint/js/transform.js

@@ -0,0 +1,153 @@
+
+
+function getVMatrixFromPoints(points) {
+    var V = new Matrix(points.length, 2);
+    for (var i=0; i < points.length; i++) {
+        V.values[0][i] = points[i][0];
+        V.values[1][i] = points[i][1];
+    }
+    return V;
+}
+
+function getSimpleUMatrixFromPoints(points) {
+    var U = new Matrix(points.length, 2);
+    for (var i=0; i < points.length; i++) {
+        U.values[0][i] = points[i][2];
+        U.values[1][i] = points[i][3];
+    }
+    return U;
+}
+
+function getProjectiveUMatrixFromPoints(points) {
+    var U = new Matrix(points.length, 3);
+    for (var i=0; i < points.length; i++) {
+        U.values[0][i] = points[i][2];
+        U.values[1][i] = points[i][3];
+        U.values[2][i] = 1;
+    }
+    return U;
+}
+
+function getQuadraticUMatrixFromPoints(points) {
+    var U = new Matrix(points.length, 5);
+    for (var i=0; i < points.length; i++) {
+        U.values[0][i] = Math.pow(points[i][2], 2);
+        U.values[1][i] = Math.pow(points[i][3], 2);
+        U.values[2][i] = points[i][2];
+        U.values[3][i] = points[i][3];
+        U.values[4][i] = 1;
+    }
+    return U;
+}
+
+function getTransform(p) {
+    if (p.length == 4) {
+        var xscale = p[0];
+        var yscale = p[1];
+        var tx = p[2];
+        var ty = p[3];
+        return {
+            type: "projective",
+            n: 4,
+            params: {
+                xscale: xscale,
+                yscale: yscale,
+                tx: tx,
+                ty: ty
+            },
+            matrix: [[xscale, 0, tx],
+                     [0, yscale, ty],
+                     [0, 0, 1]]
+        };
+
+    } else if (p.length == 5) {
+        var xscale = p[0];
+        var yscale = p[1];
+        var theta = p[2];
+        var tx = p[3];
+        var ty = p[4];
+        return {
+            type: "projective",
+            n: 5,
+            params: {
+                xscale: xscale,
+                yscale: yscale,
+                theta: theta,
+                tx: tx,
+                ty: ty,
+            },
+            matrix: [[Math.cos(theta) * xscale, -Math.sin(theta) * yscale, tx],
+                     [Math.sin(theta) * xscale, Math.cos(theta) * yscale, ty],
+                     [0, 0, 1]]
+        };
+
+    } else if (p.length == 6) {
+        return {
+            type: "projective",
+            n: 6,
+            matrix: [[p[0], p[1], p[2]],
+                     [p[3], p[4], p[5]],
+                     [0, 0, 1]]
+        };
+
+    } else if (p.length == 8) {
+        return {
+            type: "projective",
+            n: 8,
+            matrix: [[p[0], p[1], p[2]],
+                     [p[3], p[4], p[5]],
+                     [p[6], p[7], 1]]
+        };
+
+    } else if (p.length == 12) {
+        return {
+            type: "quadratic",
+            n: 12,
+            matrix: [[p[0], p[1], p[2], p[3], p[4]],
+                     [p[5], p[6], p[7], p[8], p[9]],
+                     [0, 0, p[10], p[11], 1]]
+        };
+
+    } else {
+        throw "error in getTransform: wrong number of parameters!";
+    }    
+}
+
+function applyTransform(tform, points) {
+    var U;
+    if (tform.type == "projective") {
+        U = getProjectiveUMatrixFromPoints(points);
+    } else if (tform.type == "quadratic") {
+        U = getQuadraticUMatrixFromPoints(points);
+    }
+    var height = tform.matrix.length;
+    var width = tform.matrix[0].length;
+    var T = new Matrix(width, height,
+                       tform.matrix);
+
+    /*
+    console.log(width);
+    console.log(height);
+    console.log('T: ' + JSON.stringify(T));
+    */
+
+    var Vapprox0 = T.multiply(U);
+
+    // projective rescale and truncate the bottom row
+    var n = points.length;
+    var Vapprox = new Matrix(n, 2);
+    for (var i=0; i < n; i++) {
+        var z = Vapprox0.values[2][i];
+        Vapprox.values[0][i] = Vapprox0.values[0][i] / z;
+        Vapprox.values[1][i] = Vapprox0.values[1][i] / z;
+    }
+
+    /*
+    console.log('U: ' + JSON.stringify(U));
+    console.log('T: ' + JSON.stringify(T));
+    console.log('Vapprox0: ' + JSON.stringify(Vapprox0));
+    console.log('Vapprox: ' + JSON.stringify(Vapprox));
+    */
+
+    return Vapprox;
+}