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Utilities

Module including general utilities for visualization.

This module includes the following functions:

build_cam_pyr(cam_scale, K)

Constructs a camera frustum for visualization.

needs work...

Source code in cvt/visualization/util.py 
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def build_cam_pyr(cam_scale, K):
    """Constructs a camera frustum for visualization.

    !!! bug "needs work..."
    """
    focallen   = K[0][0]
    cam_w      = 2 * K[0][2]
    cam_h      = 2 * K[1][2]
    cam_center = np.array([0.0,          0.0,          0.0,      1.0])
    cam_ul     = np.array([cam_w * -0.5, cam_h * -0.5, focallen, 1.0])
    cam_ur     = np.array([cam_w *  0.5, cam_h * -0.5, focallen, 1.0])
    cam_dr     = np.array([cam_w *  0.5, cam_h *  0.5, focallen, 1.0])
    cam_dl     = np.array([cam_w * -0.5, cam_h *  0.5, focallen, 1.0])
    cam_top    = np.array([0.0,          cam_h * -0.7, focallen, 1.0])
    cam_center *= cam_scale
    cam_ul     *= cam_scale
    cam_ur     *= cam_scale
    cam_dr     *= cam_scale
    cam_dl     *= cam_scale
    cam_top    *= cam_scale
    cam_center[3] = 1.0
    cam_ul[3]     = 1.0
    cam_ur[3]     = 1.0
    cam_dr[3]     = 1.0
    cam_dl[3]     = 1.0
    cam_top[3]    = 1.0
    cam_center = cam_center.reshape((4, 1))
    cam_ul     = cam_ul.reshape((4, 1))
    cam_ur     = cam_ur.reshape((4, 1))
    cam_dr     = cam_dr.reshape((4, 1))
    cam_dl     = cam_dl.reshape((4, 1))
    cam_top    = cam_top.reshape((4, 1))
    return [cam_center, cam_ul, cam_ur, cam_dr, cam_dl, cam_top]

build_pyr_point_cloud(pyr_pts, filename)

Builds a point cloud for a camera frustum visual.

needs work...

Source code in cvt/visualization/util.py 
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def build_pyr_point_cloud(pyr_pts, filename):
    """Builds a point cloud for a camera frustum visual.

    !!! bug "needs work..."
    """
    num_pts = len(pyr_pts)
    element_vertex = 6*num_pts
    element_edge = 10*num_pts

    with open(filename, 'w') as fh:
        # write header meta-data
        fh.write('ply\n')
        fh.write('format ascii 1.0\n')
        fh.write('comment Right-Handed System\n')
        fh.write('element vertex {}\n'.format(element_vertex))
        fh.write('property float x\n')
        fh.write('property float y\n')
        fh.write('property float z\n')
        fh.write('property uchar red\n')
        fh.write('property uchar green\n')
        fh.write('property uchar blue\n')
        fh.write('element edge {}\n'.format(element_edge))
        fh.write('property int vertex1\n')
        fh.write('property int vertex2\n')
        fh.write('property uchar red\n')
        fh.write('property uchar green\n')
        fh.write('property uchar blue\n')
        fh.write('end_header\n')

        # write vertex data to file
        for pt in pyr_pts:
            fh.write('{:.10f}'.format( pt[0][0][0] ) + ' ' + '{:.10f}'.format( pt[0][1][0] ) + ' ' + '{:.10f}'.format( pt[0][2][0] ) + ' 255 128 0\n')
            fh.write('{:.10f}'.format( pt[1][0][0] ) + ' ' + '{:.10f}'.format( pt[1][1][0] ) + ' ' + '{:.10f}'.format( pt[1][2][0] ) + ' 255 128 0\n')
            fh.write('{:.10f}'.format( pt[2][0][0] ) + ' ' + '{:.10f}'.format( pt[2][1][0] ) + ' ' + '{:.10f}'.format( pt[2][2][0] ) + ' 255 128 0\n')
            fh.write('{:.10f}'.format( pt[3][0][0] ) + ' ' + '{:.10f}'.format( pt[3][1][0] ) + ' ' + '{:.10f}'.format( pt[3][2][0] ) + ' 255 128 0\n')
            fh.write('{:.10f}'.format( pt[4][0][0] ) + ' ' + '{:.10f}'.format( pt[4][1][0] ) + ' ' + '{:.10f}'.format( pt[4][2][0] ) + ' 255 128 0\n')
            fh.write('{:.10f}'.format( pt[5][0][0] ) + ' ' + '{:.10f}'.format( pt[5][1][0] ) + ' ' + '{:.10f}'.format( pt[5][2][0] ) + ' 255 128 0\n')

        # write edge data to file
        for i in range(num_pts):
            edge_ind = i*6
            fh.write('{} {} 255 0 0\n'.format(edge_ind, edge_ind+1))
            fh.write('{} {} 255 0 0\n'.format(edge_ind, edge_ind+2))
            fh.write('{} {} 255 0 0\n'.format(edge_ind, edge_ind+3))
            fh.write('{} {} 255 0 0\n'.format(edge_ind, edge_ind+4))
            fh.write('{} {} 255 0 0\n'.format(edge_ind+1, edge_ind+2))
            fh.write('{} {} 255 0 0\n'.format(edge_ind+2, edge_ind+3))
            fh.write('{} {} 255 0 0\n'.format(edge_ind+3, edge_ind+4))
            fh.write('{} {} 255 0 0\n'.format(edge_ind+4, edge_ind+1))
            fh.write('{} {} 255 0 0\n'.format(edge_ind+1, edge_ind+5))
            fh.write('{} {} 255 0 0\n'.format(edge_ind+5, edge_ind+2))
    return

display_inlier_outlier(cloud, indices)

Displays a point cloud with outlier points colored red.

Parameters:

Name Type Description Default
cloud o3d.geometry.PointCloud

Point cloud to be displayed.

 required
indices np.ndarray

Indices indicating the inlier points.

 required
Source code in cvt/visualization/util.py 
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def display_inlier_outlier(cloud: o3d.geometry.PointCloud, indices: np.ndarray) -> None:
    """Displays a point cloud with outlier points colored red.

    Parameters:
        cloud: Point cloud to be displayed.
        indices: Indices indicating the inlier points.
    """
    inlier_cloud = cloud.select_by_index(ind)
    outlier_cloud = cloud.select_by_index(ind, invert=True)

    outlier_cloud.paint_uniform_color([1, 0, 0])
    inlier_cloud.paint_uniform_color([0.8, 0.8, 0.8])
    o3d.visualization.draw_geometries([inlier_cloud, outlier_cloud],
                                      zoom=0.3412,
                                      front=[0.4257, -0.2125, -0.8795],
                                      lookat=[2.6172, 2.0475, 1.532],
                                      up=[-0.0694, -0.9768, 0.2024])

    return

display_map(filename, disp_map, mx, mn)

Writes an input map to a normalized image.

Parameters:

Name Type Description Default
filename str

Name of the file to store the input map.

 required
disp_map np.ndarray

Map to be stored as an image file.

 required
mx float

maximum value used for pixel intensity normalization.

 required
mn float

minimum value used for pixel intensity normalization.

 required
Source code in cvt/visualization/util.py 
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def display_map(filename: str, disp_map: np.ndarray, mx: float, mn: float) -> None:
    """Writes an input map to a normalized image.

    Parameters:
        filename: Name of the file to store the input map.
        disp_map: Map to be stored as an image file.
        mx: maximum value used for pixel intensity normalization.
        mn: minimum value used for pixel intensity normalization.
    """
    disp_map = ((disp_map-mn)/(mx-mn+1e-8))*255
    cv2.imwrite(filename, disp_map)