Showing papers by "Faisal Shafait published in 2004"
31 Jul 2004
TL;DR: In this article, a vision-based approach for fault detection of empty water bottles is presented, where the main constraint is the real-time operation as the bottles move continuously on the conveyer belt.
Abstract: The paper presents a vision-based approach for fault detection of empty water bottles. Our goal is to find all defects in the empty water bottles. The main constraint is the real time operation as the bottles move continuously on the conveyer belt. Using camera images, we first find the position of the bottle in the image by a generalized Hough transform. Then we check the bottles for any defects or the presence of alien objects using rectangular and circular area intensity inspection. Bottles with any defects are rejected and so separated from the main stream. In the statistics obtained, our inspection system successfully rejected all the faulty or defective bottles. The good bottle rejection rate was lower than 1% of the total number of bottles inspected. This system can be used for inspecting any type of empty bottles for defects or the presence of alien objects.
30 citations
24 Dec 2004
TL;DR: This contribution presents a low-complexity camera egomotion estimation algorithm for real-time applications which uses a feature based approach for motion estimation and a new method is introduced for feature selection which limits the number of feature points to be tracked and has a low dependency on structure in the image.
Abstract: This contribution presents a low-complexity camera egomotion estimation algorithm for real-time applications. The algorithm uses a feature based approach for motion estimation. A new method is introduced for feature selection which limits the number of feature points to be tracked and has a low dependency on structure in the image. Both these factors are important in real time, applications, as lesser features to track result in lower computational complexity and lesser dependency on image structure results in smaller variations in computational time for different images. This gain in speed is achieved at the cost of a slightly reduced robustness and accuracy. This trade-off between speed and accuracy pays off particularly in static scenes where high reduction in computational cost is achieved without the accuracy penalty. This algorithm can be used in applications where an estimate of camera motion is required and low computational complexity is of primary concern.
5 citations
18 Dec 2004
TL;DR: A two-step vision-based approach for real time inspection of the assembled valve keys in automobile cylinder heads successfully differentiated between true negatives and false negatives, reducing false negatives to 0%.
Abstract: This paper presents a two-step vision-based approach for real time inspection of the assembled valve keys in automobile cylinder heads. In the first step a combination of Sobel edge detector with gradient pair vector method is used for the detection of circular shaped valve keys. This method is very fast but also highly sensitive to noise, resulting in a relatively high percentage of false negatives. The second inspection step employs Canny edge detector with circular Hough transform. The images of the valve keys rejected in the first step pass through the second inspection step. This procedure differentiates between the false negatives and the true negatives. The cylinder heads rejected in the second step are separated afterwards from the main stream of the transportation line. In the statistics obtained, the first inspection step successfully rejected all of the wrongly assembled valve keys. The false rejection rate was around 4.6% of the total number of the valve keys rejected. The second inspection step successfully differentiated between true negatives and false negatives, reducing false negatives to 0%.
2 citations
31 Jul 2004
TL;DR: The paper presents a vision-based approach for real time inspection and recognition of the assembled valve keys in automobile cylinder heads and successfully rejected most of the wronglyassembled valve keys.
Abstract: The paper presents a vision-based approach for real time inspection and recognition of the assembled valve keys in automobile cylinder heads. The vision solution should be flexible enough to adapt with the valve keys of different cylinder head types according to the requirements. The vision investigation includes cameras, infrared illumination, and an image-processing algorithm. The results of the image-processing algorithm show that either it has found the valve keys in its correct assembled position or not. The total number of correctly positioned valve keys that have been passed by the vision station is also calculated. The inspection is done in real time as cylinder heads are continuously moving on the transportation line. Using images obtained from the camera, we first find the position of the center point of the tappet. Then as a first check angular misalignment of the valve shaft is found out and ultimately as a final check diameter of the valve key is found out. The rejected cylinder heads from the vision station were separated afterwards from the main stream of the transportation line. In the statistics obtained, the vision solution has successfully rejected most of the wrongly assembled valve keys. The false rejection rate was also lower than 0.2% of the total number of the valve keys investigated.