Fixed: overflow errors in depth values

[alters-mit]

Closes #52

Steps to reproduce

Run this controller:

from PIL import Image
import numpy as np
from tdw.controller import Controller
from tdw.tdw_utils import TDWUtils
from tdw.output_data import OutputData, Images

class DepthValues(Controller):
    def run(self):
        # Create the scene.
        # Set image encoding globals.
        self.start()
        commands = [TDWUtils.create_empty_room(12, 12)]
        # Create the avatar.
        commands.extend(TDWUtils.create_avatar(position={"x": 2.478, "y": 1.602, "z": 1.412},
                                               look_at=TDWUtils.VECTOR3_ZERO,
                                               avatar_id="a"))
        # Enable all pass masks. Request an image for this frame only.
        commands.extend([{"$type": "set_pass_masks",
                          "pass_masks": ["_depth"],
                          "avatar_id": "a"},
                         {"$type": "send_images",
                          "ids": ["a"],
                          "frequency": "once"}])
        # Add objects.
        commands.append(self.get_add_object("small_table_green_marble",
                                            position=TDWUtils.VECTOR3_ZERO,
                                            rotation=TDWUtils.VECTOR3_ZERO,
                                            object_id=0))
        commands.append(self.get_add_object("rh10",
                                            position={"x": 0.7, "y": 0, "z": 0.4},
                                            rotation={"x": 0, "y": 30, "z": 0},
                                            object_id=1))
        # Send the commands.
        resp = self.communicate(commands)
        # Save the images.
        for r in resp[:-1]:
            r_id = OutputData.get_data_type_id(r)
            if r_id == "imag":
                images = Images(r)
                for i in range(images.get_num_passes()):
                    if images.get_pass_mask(i) == "_depth":
                        depth_values = TDWUtils.get_depth_values(images.get_image(i))
                        depth_values /= (depth_values.max() / 255)
                        q = np.uint8(depth_values)
                        qq = np.uint8(np.empty((q.shape[0], q.shape[1], 3)))
                        qq[:, :, 0] = q
                        qq[:, :, 1] = q
                        qq[:, :, 2] = q
                        image = Image.fromarray(qq)
                        image.show()
        # Stop the build.
        self.communicate({"$type": "terminate"})


if __name__ == "__main__":
    DepthValues().run()

Result: Converting the depth values back to grayscale produces a reasonable-looking image (implying that the calculation is correct).

Changes

tdw module

TDWUtils

• Fixed: Overflow of values in get_depth_values()

[cffan]

Does it make more sense to use np.float? Since depth is a real value.

[alters-mit]

@cffan There's no difference.

img_0 = np.array(Image.open(io.BytesIO(image)), dtype=np.float)
depth_0 = np.array((img_0[:, :, 0] * 256 * 256 + img_0[:, :, 1] * 256 + img_0[:, :, 2]) / (256 * 256 * 256) * 100.1)

img_1 = np.array(Image.open(io.BytesIO(image)), dtype=np.uint32)
depth_1 = np.array((img_1[:, :, 0] * 256 * 256 + img_1[:, :, 1] * 256 + img_1[:, :, 2]) / (256 * 256 * 256) * 100.1)

print(np.linalg.norm(depth_0 - depth_1))

Result: 0.0