LaurentBerger
commented
2 weeks ago No error update your opencv version
import numpy as np
import cv2 as cv
yolov8n = cv.dnn.readNet("yolov8n.onnx")
yolov8n.setPreferableBackend(cv.dnn.DNN_BACKEND_OPENCV)
yolov8n.setPreferableTarget(cv.dnn.DNN_TARGET_CPU)
img = cv.imread(cv.samples.findFile('squirrel_cls.jpg'))
paramYolov8n = cv.dnn.Image2BlobParams()
paramYolov8n.ddepth = cv.CV_32F
paramYolov8n.borderValue = 0
paramYolov8n.paddingmode = cv.dnn.DNN_PMODE_NULL
paramYolov8n.datalayout = cv.dnn.DNN_LAYOUT_NCHW
paramYolov8n.mean = (0, 0, 0)
paramYolov8n.scalefactor = (1. / 255, 1. / 255, 1. / 255)
paramYolov8n.size = (640, 640)
paramYolov8n.swapRB = True
blobIn = cv.dnn.blobFromImageWithParams(img, paramYolov8n)
yolov8n.setInput(blobIn)
out = yolov8n.forward()
yolov8n_cuda = cv.dnn.readNet("yolov8n.onnx")
yolov8n_cuda.setPreferableBackend(cv.dnn.DNN_BACKEND_CUDA)
yolov8n_cuda.setPreferableTarget(cv.dnn.DNN_TARGET_CUDA)
yolov8n_cuda.setInput(blobIn)
out_cuda = yolov8n_cuda.forward()
print("Quadratic error ", np.mean((out[0]-out_cuda[0])**2))
print("Max error ", np.max(np.abs(out[0]-out_cuda[0])))Quadratic error 5.6130234e-10 Max error 0.0027160645
123467895
fengyuentau
System Information
// example for c++ user OpenCV version: 4.9.0 Operating System / Platform: Ubuntu 20.04 /Windwos11 Compiler & compiler version: GCC 9.3.0
Detailed description
The model is yolov8n.pt from the official YOLOv8 website. It was exported using the command "yolo detect export model=yolov8n.pt format=onnx opset=12".
use cpu： set “this->net.setPreferableBackend(cv::dnn::DNN_BACKEND_OPENCV); this->net.setPreferableTarget(cv::dnn::DNN_TARGET_CPU);” The results are correct. Partial results screenshot：
4 coordinates + 80 class probabilities
use CUDA： set “this->net.setPreferableBackend(cv::dnn::DNN_BACKEND_CUDA); this->net.setPreferableTarget(cv::dnn::DNN_TARGET_CUDA);” The results are error. Partial results screenshot：
The probabilities are present, but all 4 coordinates are 0. The coordinates are missing.
image：
model: yolov8n.zip
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