Computer vision systems based on convolutional neural networks are being rapidly introduced in the field of precision agriculture to solve the problem of scene recognition. Convolutional networks allow performing high-precision recognition, but a significant problem is the expensive process of adapting the network to new conditions. This article proposes a method of fast adaptation of the trained network to minor changes in the source domain without annotating new data. This method is known as Adversarial Domain Adaptation, in the current paper it is applied to the problem of agricultural scene recognition in automated harvesting. The initial training procedure is modified for parallel training of an additional subnet on unannotated data, which makes it possible to compensate the domain shift due to adversarial training. This approach allows us to monotonically increase the quality of all recognized classes of objects and to enhance the stability of CNN model.
Publisher’s Note: This paper, originally published on 13 April 2018, was replaced with a corrected/revised version on 14 September 2018. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.
The paper proposes a solution to the automatic operation of the combine harvester along the straw rows by means of the images from the camera, installed in the cab of the harvester. The U-Net is used to recognize straw rows in the image. The edges of the row are approximated in the segmented image by the curved lines and further converted into the harvester coordinate system for the automatic operating system. The “new” network architecture and approaches to the row approximation has improved the quality of the recognition task and the processing speed of the frames up to 96% and 7.5 fps, respectively. Keywords: Grain harvester,
We study the issue of performance improvement of classification-based object detectors by including certain geometric-oriented filters. Configurations of the observed 3D scene may be used as a priori or a posteriori information for object filtration. A priori information is used to select only those object parameters (size and position on image plane) that are in accordance with the scene, restricting implausible combinations of parameters. On the other hand the detection robustness can be enhanced by rejecting detection results using a posteriori information about 3D scene. For example, relative location of detected objects can be used as criteria for filtration. We have included proposed filters in object detection modules of two different industrial vision-based recognition systems and compared the resulting detection quality before detectors improving and after. Filtering with a priori information leads to significant decrease of detector's running time per frame and increase of number of correctly detected objects. Including filter based on a posteriori information leads to decrease of object detection false positive rate.