def make_rois_tile_cell_relative()

in 04_detect_segment/utils_box.py [0:0]

• 15 lines of code
• 2 McCabe index (conditional complexity)

def make_rois_tile_cell_relative(tile, tiled_rois, grid_n):
    grid, cell_w = gen_grid_for_tile(tile, grid_n)
    tile_w = cell_w * grid_n

    # tiled_rois shape [grid_n, grid_n, cell_n, 3]

    # compute grid cell centers
    grid_centers = (grid + grid + cell_w) / 2.0  # shape [grid_n, grid_n, 2]

    gc_x, gc_y = tf.unstack(grid_centers, axis=-1)  # shape [grid_n, grid_n]
    # force broadcasting on correct axis
    gc_x = tf.expand_dims(gc_x, axis=-1)
    gc_y = tf.expand_dims(gc_y, axis=-1)
    tr_x, tr_y, tr_w = tf.unstack(tiled_rois, axis=-1) # shape [grid_n, grid_n, cell_n]

    ctr_x = (tr_x - gc_x) / (cell_w/2.0)  # constrain x within [-1, 1] in cell center relative coordinates
    ctr_y = (tr_y - gc_y) / (cell_w/2.0)  # constrain y within [-1, 1] in cell center relative coordinates
    ctr_w = tr_w / tile_w  # constrain w within [0, 1] in tile-relative coordinates

    # leave x, y coordinates unchanged (as 0) if the width is zero (empty box)
    ctr_x = tf.where(tf.greater(tr_w, 0), ctr_x, tr_x)
    ctr_y = tf.where(tf.greater(tr_w, 0), ctr_y, tr_x)

    rois = tf.stack([ctr_x, ctr_y, ctr_w], axis=-1)
    return rois