Reopening capture depth+RGB images

Hello,
for one of my projects I've created a simple box (50X30X50mm) for which i want to create a syntactic RGBD data set.
using the following code:
```
import open3d as o3d
# Load my model
mesh = o3d.io.read_triangle_mesh("../Pointcloud_data_creator/models/box_meter.ply")
o3d.visualization.draw_geometries([mesh])

# Change the file names by hand

# Open the saved rgb+image+json
color_raw = o3d.io.read_image('../Pointcloud_data_creator/rgb.png')
depth_raw = o3d.io.read_image('../Pointcloud_data_creator/depth.png')

rgbd_image = o3d.geometry.RGBDImage.create_from_color_and_depth(color_raw, depth_raw)

parameters = o3d.io.read_pinhole_camera_parameters('../Pointcloud_data_creator/test.json')
pcd = o3d.geometry.PointCloud.create_from_rgbd_image(rgbd_image,parameters.intrinsic)
o3d.visualization.draw_geometries([pcd])
```

I've captured, using the functions in the visualizer, an rgb+depth+json file which i renamed by hand.
then when i try to reopen them using create_from_rgbd_image i get a blank screen. (i know I'm currently not setting my camera extrinsic matrix but that's a problem for another day)
am i missing something? (from playing around with it for a little it seems i get an empty point cloud because the depth's in the depth image are set incorrectly)