How to get values from type "jetson.inference.detectNet.Detection"

[Totemi1324]

I use DetectNet on my Jetson Nano which works well. The net.Detect() funcion gives back a list where each object is from type "jetson.inference.detectNet.Detection". When I print it:

<detectNet.Detection object>
   -- ClassID: 1
   -- Confidence: 0.808974
   -- Left:    416.31
   -- Top:     218.694
   -- Right:   593.188
   -- Bottom:  703.127
   -- Width:   176.878
   -- Height:  484.433
   -- Area:    85685.7
   -- Center:  (504.749, 460.91)

Now my question is: How can I access these values separately (e.g. only the ClassID which, in this case, would be 1)? Lines like detection[0][0] don't work, since it is not an array. I want to count how many objects of each class were detected. Thanks!

[leandrovrabelo]

I have the same problem and I still didn't find how to get these values, I want to use these information to create a map.

[leandrovrabelo]

Hi, I jus found out how to capture these values, after creating an object, you access the values on the list calling [0]` and then you grab the variable that you want, see bellow the example:

detections[0].ClassID

the options that you have are: ClassID, Confidence, Left, Right, Width, Height, Bottom, Area and Center.

Leandro.

[Totemi1324]

Thank you so much for sharing! It's working for me 👍

[OussamaBATOUCHE]

Hi, I jus found out how to capture these values, after creating an object, you access the values on the list calling [0]` and then you grab the variable that you want, see bellow the example:

detections[0].ClassID

the options that you have are: ClassID, Confidence, Left, Right, Width, Height, Bottom, Area and Center.

Leandro.

please can you help me to find this classId lable ?

[leandrovrabelo]

After creating an object like detection = net.Detect() you can use a for loop to extract these information:

ids = []
for info in detection:
ids.append(detection[info].ClassID)

If you have many detections in the same images it will show a list of the IDs

[MaahirG]

The coco dataset classIDs are here: [https://tech.amikelive.com/node-718/what-object-categories-labels-are-in-coco-dataset/]

1 = person, 3 = car etc.

This directly corresponds to the ClassID you get in detection[0].ClassID
Hope this helps!

[Jason-xy]

After creating an object like detection = net.Detect() you can use a for loop to extract these information:

ids = []
for info in detection:
ids.append(detection[info].ClassID)

If you have many detections in the same images it will show a list of the IDs

First, thanks for your answer, but when I tried this it told me ' list indices must be integers or slices, not jetson.inference.detectNet.Detection'. Did you solve this problem?

[leandrovrabelo]

@Jason-xy could you put all the steps of your code?

[Jason-xy]

@Jason-xy could you put all the steps of your code?

Thanks for your reply, the following is my code：

net = jetson.inference.detectNet("ssd-mobilenet-v2", threshold=0.5)
camera = jetson.utils.videoSource("csi://0")
display = jetson.utils.videoOutput("display://0") 
info = jetson.utils.cudaFont()
speed=0.0
while display.IsStreaming():
	img = camera.Capture()
	detections = net.Detect(img)
	for i in detections:
		info.OverlayText(img, 5, 5,"speed:{:.2f}".format(speed), detections[i].Bottom, detections[i].Right, info.White, info.Gray40)
	display.Render(img)
	display.SetStatus("Object Detection | Network {:.0f} FPS".format(net.GetNetworkFPS()))

[Jason-xy]

@Jason-xy could you put all the steps of your code?

Thanks for your reply, I have successfully solved this problem. Because I am not familiar with the syntax of python and made this stupid mistake, the modified code is as follows:

net = jetson.inference.detectNet("ssd-mobilenet-v2", threshold=0.5)
camera = jetson.utils.videoSource("csi://0")
display = jetson.utils.videoOutput("display://0") 
info = jetson.utils.cudaFont()
speed=0.0
while display.IsStreaming():
	img = camera.Capture()
	detections = net.Detect(img)
	for detection in detections:
		info.OverlayText(img, 5, 5,"speed:{:.2f}".format(speed),int(detection.Left)+5, int(detection.Top)+35, info.White, info.Gray40)
	display.Render(img)
	display.SetStatus("Object Detection | Network {:.0f} FPS".format(net.GetNetworkFPS()))

[Ncnguyen-max]

hi,
how can i print out like this value?
<detectNet.Detection object>
-- ClassID: 1
-- Confidence: 0.808974
-- Left: 416.31
-- Top: 218.694
-- Right: 593.188
-- Bottom: 703.127
-- Width: 176.878
-- Height: 484.433
-- Area: 85685.7
-- Center: (504.749, 460.91)

[Totemi1324]

hi,
how can i print out like this value?
<detectNet.Detection object>
-- ClassID: 1
-- Confidence: 0.808974
-- Left: 416.31
-- Top: 218.694
-- Right: 593.188
-- Bottom: 703.127
-- Width: 176.878
-- Height: 484.433
-- Area: 85685.7
-- Center: (504.749, 460.91)

Hi, you can print out the individual items of the list returned by net.Detect() if this is what you're looking for.

detections = net.Detect(img)
for detection in detections:
	print(detection)

[Ncnguyen-max]

hi,
how can i print out like this value?
<detectNet.Detection object>
-- ClassID: 1
-- Confidence: 0.808974
-- Left: 416.31
-- Top: 218.694
-- Right: 593.188
-- Bottom: 703.127
-- Width: 176.878
-- Height: 484.433
-- Area: 85685.7
-- Center: (504.749, 460.91)

Hi, you can print out the individual items of the list returned by net.Detect() if this is what you're looking for.

detections = net.Detect(img)
for detection in detections:
	print(detection)

thanks you so much

[indramal]

This is code for get Class ID and Class Lable from Jetson Infecrence detectNet.

This will show class label - print(net.GetClassDesc(detection.ClassID))
This will show class ID - print(detection.ClassID)

import jetson.inference
import jetson.utils

net = jetson.inference.detectNet("ssd-mobilenet-v2", threshold=0.5)
camera = jetson.utils.videoSource("v4l2:///dev/video0")
display = jetson.utils.videoOutput("display://0") 
info = jetson.utils.cudaFont()
speed=0.0
while display.IsStreaming():
	img = camera.Capture()
	detections = net.Detect(img)
	for detection in detections:
		print(net.GetClassDesc(detection.ClassID))
		print(detection.ClassID)
		info.OverlayText(img, 5, 5,"speed:{:.2f}".format(speed),int(detection.Left)+5, int(detection.Top)+35, info.White, info.Gray40)
	display.Render(img)
	display.SetStatus("Object Detection | Network {:.0f} FPS".format(net.GetNetworkFPS()))