Topics

1

Python and Java API / GUI and API Red-edge and Blue pixel values different

« on: October 12, 2023, 11:04:35 PM »

Hello,
I am testing the results of GUI vs API processing of Micasense imagery. I use different shapefiles placed over the image to compare the pixel values of each band (using raster zonal stats). There are 5 bands: blue, green, red, red-edge, and nir.
The green and red orthomosaic results are great and the pixel averages for the shapefiles match well, the red-edge is also okay.
The issue is that the orthomosaic blue and nir pixels values are quite different for the shapefile areas. I manually set the whiteboard albedo in both the GUI and API {"Blue": "0.66", "Green": "0.67", "Red": "0.67", "NIR": "0.67", "Red edge": "0.63"}. Is there any other possibility of why this might be happening? Here is the code used for this step:



albedo = {"Green": "0.67", "Red": "0.67", "NIR": "0.63", "Red edge": "0.67"}

for camera in chunk.cameras:
    if camera.group and camera.group.label == "Calibration images":
        for plane in camera.planes:
            plane.meta["ReflectancePanel/Calibration"] = albedo[plane.sensor.bands[0]]

for sensor in chunk.sensors:
    sensor.normalize_sensitivity = True

task = Metashape.Tasks.CalibrateReflectance()
task.use_reflectance_panels = True
task.use_sun_sensor = True
task.apply(chunk)
doc.save()

for sensor in chunk.sensors:
    sensor.normalize_sensitivity=True

chunk.locateReflectancePanels()
chunk.calibrateReflectance(use_reflectance_panels=True, use_sun_sensor=True)
doc.save()



Thanks in advance!
- Robin

2

Python and Java API / Is there a downscale or equivalent parameter for buildDem?

« on: October 06, 2023, 05:31:55 PM »

Howdy everyone,
I was reading the Metashape Python reference and couldn't find any info on a downscale or equivalent parameter for the buildDem function  . I am trying to match my Python script to the gui. Is there an equivalent?
Thanks in advance! - Robina

3

Python and Java API / Python and software results do not match (downscale parameters?)

« on: September 18, 2023, 08:09:07 PM »

I can't understand why the Python and software orthomosaic results are not matching.
I've tested different downscale parameters, but it looks like some functions like buildPointCloud and buildDem do not have these.
The Metashape Python Reference says nothing about these parameters (at least from what I've read). I'd suggest adding explanations of these into the Reference.
Could the lack of a downscale parameter be why I am consistently receiving incorrect results?

TIA
Robin

4

Python and Java API / Python api and software orthomosaics not aligned

« on: August 18, 2023, 11:35:55 PM »

I am processing micasense imagery using the python api. The resulting python orthomosaic does not align correctly with the one processed in the software. They overlap, but there is a small offset. The defined parameters should all be the same. Is there any reason this could be happening?

Thanks,
Robina

 

5

Python and Java API / How to determine if calibrateReflectance parameters are correctly applied?

« on: August 18, 2023, 06:55:09 PM »

For the calibrateReflectance function, how do I determine if "use_reflectance_panels" and "use_sun_sensor" is applied when I set them as True in the script?
Is there any way to check in the metashape project?

Thanks,
Rob