Example #1
0
  /**
   * Performs an exhaustive search centered around (cx,cy) for the region in 'curr' which is the
   * best match for the template. Results are written into 'flow'
   */
  protected float findFlow(int cx, int cy, T curr, ImageFlow.D flow) {
    float bestScore = Float.MAX_VALUE;
    int bestFlowX = 0, bestFlowY = 0;

    for (int i = -searchRadius; i <= searchRadius; i++) {
      int y = cy + i;
      for (int j = -searchRadius; j <= searchRadius; j++) {
        int x = cx + j;
        float error = computeError(x, y, curr);
        if (error < bestScore) {
          bestScore = error;
          bestFlowX = j;
          bestFlowY = i;
        } else if (error == bestScore) {
          // Pick solution with the least motion when ambiguous
          float m0 = j * j + i * i;
          float m1 = bestFlowX * bestFlowX + bestFlowY * bestFlowY;
          if (m0 < m1) {
            bestFlowX = j;
            bestFlowY = i;
          }
        }
      }
    }

    if (bestScore <= maxError) {
      flow.valid = true;
      flow.x = bestFlowX;
      flow.y = bestFlowY;
      return bestScore;
    } else {
      flow.valid = false;
      return Float.NaN;
    }
  }
  @Test
  public void checkNeighbors() {
    int r = 3;
    Dummy alg = new Dummy(r, 2, 200, ImageUInt8.class);

    alg.scores = new float[20 * 30];
    ImageFlow flows = new ImageFlow(20, 30);
    ImageFlow.D tmp = new ImageFlow.D();

    tmp.valid = true;
    tmp.x = -1;
    tmp.y = 2;

    // checks to see if a pixel is invalid that it's flow is always set
    // if a pixel is valid then the score is only set if the score is better
    flows.get(6, 5).valid = true;
    alg.scores[5 * 20 + 6] = 10;
    flows.get(5, 5).valid = true;
    alg.scores[5 * 20 + 5] = 4;
    // same score, but more motion
    flows.get(5, 6).valid = true;
    alg.scores[6 * 20 + 5] = 5;
    flows.get(5, 6).x = 2;
    flows.get(5, 6).y = 2;
    // same score, but less motion
    flows.get(6, 6).valid = true;
    alg.scores[6 * 20 + 6] = 5;
    flows.get(6, 6).x = 0;
    flows.get(6, 6).y = 1;

    alg.checkNeighbors(6, 7, tmp, flows, 5);

    for (int i = -r; i <= r; i++) {
      for (int j = -r; j <= r; j++) {
        int x = j + 6;
        int y = i + 7;

        ImageFlow.D f = flows.get(x, y);

        assertTrue(f.valid);
        if (x == 5 && y == 5) {
          assertEquals(4, alg.scores[y * 20 + x], 1e-4);
          assertEquals(0, f.x, 1e-4);
          assertEquals(0, f.y, 1e-4);
        } else if (x == 6 && y == 6) {
          assertEquals(5, alg.scores[y * 20 + x], 1e-4);
          assertEquals(0, f.x, 1e-4);
          assertEquals(1, f.y, 1e-4);
        } else {
          assertEquals(x + " " + y, 5, alg.scores[y * 20 + x], 1e-4);
          assertEquals(-1, f.x, 1e-4);
          assertEquals(2, f.y, 1e-4);
        }
      }
    }
  }