Switched camera_info for rect image data pub

[youliangtan]

Hi, this is just regarding about the ros camera_info data pub issue. I have noticed that the camera_info is switched in here while publishing it with the rectified topics.

  calibration_data_.getDepthCameraInfo(rgb_rect_camera_info);
  calibration_data_.getRgbCameraInfo(depth_rect_camera_info);

Refer to here

While the raw images topics are publishing the "correct" camera_info, the rectified images seems to be switched. I supposed it should be the other way as such

  calibration_data_.getDepthCameraInfo(depth_rect_camera_info);
  calibration_data_.getRgbCameraInfo(rgb_rect_camera_info);

I am also quite unsure, please correct me if I am wrong with this.

[ooeygui]

It looks like this was an oversight during the implementation. Good catch! How does this bug manifest for you?

[youliangtan]

This is not significant to people who directly subcribe to the published pointcloud. For me, it doesnt affect my application. But if anyone is planning to use the camera_info of rect images, this will be confusing to them. Cheers!

[christian-rauch]

I am using the camera intrinsics to do the projection myself. Since the sensor is factory calibrated, there is only a single set of intrinsic parameters per camera ({rgb,ir}/camera_info). The remaining intrinsics should be derived from the registration into the respective camera frames:

• depth ← ir (depth is derived from the IR image)
• depth_to_rgb ← rgb (depth data is assigned to pixels in the colour frame)
• rgb_to_depth ← rgb (colour data is assigned to pixels in the depth/ir frame)

The rgb/camera_info and ir/camera_info are correctly assigned from getRgbCameraInfo and getDepthCameraInfo respectively.

rgb_to_depth, which registers the colour in the depth frame (assigns colour to depth data), uses getDepthCameraInfo which is correct. depth_to_rgb, which registered the depth in the colour frame (assigns depth to the colour data), uses getRgbCameraInfo which is also correct.

All this seems correct. But I agree that the "rect" variable naming is very confusing because depth_rect_camera_info is actually the calibrated RGB image and rgb_rect_camera_info is actually the calibrated IR image.

You could simply assign the "rect" intrinsics from the original rgb and ir intrinsics, leaving a comment why this is done.

@ooeygui Any chance that his variable naming gets fixed?