| Literature DB >> 23202040 |
Mercè Teixidó1, Davinia Font, Tomàs Pallejà, Marcel Tresanchez, Miquel Nogués, Jordi Palacín.
Abstract
This work proposes the development of an embedded real-time fruit detection system for future automatic fruit harvesting. The proposed embedded system is based on an ARM Cortex-M4 (STM32F407VGT6) processor and an Omnivision OV7670 color camera. The future goal of this embedded vision system will be to control a robotized arm to automatically select and pick some fruit directly from the tree. The complete embedded system has been designed to be placed directly in the gripper tool of the future robotized harvesting arm. The embedded system will be able to perform real-time fruit detection and tracking by using a three-dimensional look-up-table (LUT) defined in the RGB color space and optimized for fruit picking. Additionally, two different methodologies for creating optimized 3D LUTs based on existing linear color models and fruit histograms were implemented in this work and compared for the case of red peaches. The resulting system is able to acquire general and zoomed orchard images and to update the relative tracking information of a red peach in the tree ten times per second.Entities:
Mesh:
Year: 2012 PMID: 23202040 PMCID: PMC3545611 DOI: 10.3390/s121014129
Source DB: PubMed Journal: Sensors (Basel) ISSN: 1424-8220 Impact factor: 3.576
Figure 1.The camera module, the board processor and the auxiliary color LCD.
Figure 2.The camera module with the FIFO memory at the back.
Figure 3.The processor used in the embedded system.
Figure 4.Red peach segmentation LUT obtained from linear color models.
Figure 5.Red peach segmentation LUT obtained from a three-dimensional histogram.
Figure 6.Orchard image (320 × 240 pixels, RGB565) obtained in normal (a) and zoom mode (b).
Segmentation algorithm, time required to perform the operations and the real frame rate achieved.
| Image copy from the FIFO to processor memory | 40.30 | 10 |
| Image reading from the FIFO + | 44.28 | 10 |
| Image reading from the FIFO + | 46.61 | 10 |
| Image reading from the FIFO + | 52.23 | 10 |
| Image reading from the FIFO + | 44.41 | 10 |
| Image reading from the FIFO + | 51.73 | 10 |
| Image reading from the FIFO + | 63.64 | 10 |
| Image reading from the FIFO + | 2,228.47 | 0.44 |
Average relative error in the area estimate of red peaches for different illuminations.
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|---|---|---|
| Bright Illumination | 9.86% | 6.42% |
| Low Illumination | 7.89% | 7.59% |
Average noisy pixels in the segmented image for different occlusions.
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| ||
|---|---|---|
| Occlusion ratio lower than 33% | 3.37% | 5.99% |
| Occlusion ratio from 33% to 66% | 5.51% | 8.97% |
| Occlusion ratio from 66% to 99% | 7.82% | 10.87% |
Average relative error in the area estimate of red peaches for different occlusions.
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| ||
|---|---|---|
| Occlusion ratio lower than 33% | 7.77% | 7.80% |
| Occlusion ratio from 33% to 66% | 12.43% | 13.64% |
| Occlusion ratio from 66% to 99% | 21.36% | 23.20% |
Average noisy pixels in the segmented image for different illuminations.
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|---|---|---|
| Bright Illumination | 3.40% | 5.71% |
| Low Illumination | 4.76% | 7.81% |