def ProcessFrame(self, frame):
"""Searches for vehicles in the provided video frame and draws their bounding boxes.
Args:
frame: The video frame to process.
"""
# the frame needs to be converted to the format that was used during training: float [0.0, 1.0]
frame = frame.astype(np.float32) / 255.0
self.hotWindows = []
window_sizes = ((6, 6), (10, 10), (12, 12))
overlaps = ((0.25, 0.25), (0.125, 0.125), (0.125, 0.125))
y_ranges = ((0.55, 0.7), (0.55, 0.8), (0.5, 0.95))
x_ranges = ((0.5, 1.0), (0.5, 1.0), (0.4, 1.0))
# loop through all window sizes and search the image
for window, overlap, y_range, x_range in zip(window_sizes, overlaps,
y_ranges, x_ranges):
scene = Scene(frame,
window_size=window,
color_space=self.colorSpace,
hog_color_channel=self.hogColorChannel)
h, a = scene.SearchWindows(y_range, x_range, overlap,
self.classifier)
self.hotWindows.append(h)
# get the heatmap for the current frame and add it to the historical frames
heatmap = scene.DrawHeatMap(self.hotWindows)
self.heatmapQueue.appendleft(
np.zeros(shape=self.heatmapSize, dtype=np.float32))
for hmap in self.heatmapQueue:
hmap += heatmap
# finally, get the detected regions from the multi-frame heatmap
detected_regions = scene.GetLabeledRegions(
heatmap=self.heatmapQueue.pop(), threshold=self.threshold)
detected_regions = self._sanitizeRegions(detected_regions)
# extract the windows from the detected_regions and low-pass filter them WRT time
if self.previousRegions is not None and len(
self.previousRegions) == len(detected_regions[1]):
try:
filtered_regions = self._filterRegions(detected_regions)
out_frame = scene.DrawWindows([filtered_regions])
self.previousRegions = filtered_regions[1]
except ValueError:
out_frame = scene.DrawWindows([detected_regions])
self.previousRegions = detected_regions[1]
else:
# there is a mis-match in number of detected regions so just ignore the previous regions
out_frame = scene.DrawWindows([detected_regions])
self.previousRegions = detected_regions[1]
# format the return image for video stream
return np.uint8(out_frame * 255)
def DrawPositiveDetections(self, frame):
scene = Scene(frame)
return scene.DrawWindows(self.hotWindows)
