• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.10
• /
• pp.1551-1560
• /
• 1997

This study is devoted to the detection of the 3-dimensional point obstacles on the plane by using accumulated scan line images. The proposed accumulating only one scan line allow to process image at real time. And the change of motion of the feature in image is small because of the short time between image frames, so it does not take much time to track features. To obtain recursive optimal obstacles position and robot motion along to the motion of camera, Kalman filter algorithm is used. After using Kalman filter in case of the fixed environment, 3-dimensional obstacles point map is obtained. The position and motion of moving obstacles can also be obtained by pre-segmentation. Finally, to solve the stereo ambiguity problem from multiple matches, the camera motion is actively used to discard mis-matched features. To get relative distance of obstacles from camera, parallel stereo camera setup is used. In order to evaluate the proposed algorithm, experiments are carried out by a small test vehicle.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.687-690
• /
• 2002

본 논문은 자동으로 볼트를 검사할 수 있는 장치에 대한 시스템 설계 및 제품 개발에 관해 다룬다. 볼트를 연속적으로 검사하기 위해 컨베이어를 이용하고 이를 동작시키기 위한 서보모터와 엔코더를 부착하여 정확한 이송량를 유지하게 된다. 엔코더 신호를 수신한 라인스캔 카메라의 동작에 따라 프레임 그래버로 볼트 영상을 전송하며 한 프레임을 구성한 후 영상 검사 알고리즘에 의해 파라메터를 측정하고 검사하게 된다. 제작된 결과물을 이용하여 실험을 통해 본 장치의 효용성을 입증하고자 한다.

• Proceedings of the IEEK Conference
• /
• 2000.09a
• /
• pp.873-876
• /
• 2000

본 논문에서는 양방향 움직임 보상에 의한 필드 보간(bi-directional motion-compensated field interpolation) 방법을 사용한 효과적인 디인터레이싱(de-interlacing) 기법을 제안한다. 움직임 추정(motion estimation)을 이용한 일반적인 디인터레이싱 기법은 서로 다른 샘플링 격자(sampling grid) 관계인 연속한 두 필드(field)들간의 움직임 추정을 위해 line average 같은 비교적 간단한 형태의 디인터레이싱 기법이 선행된다. 그러나, 제안한 방법은 보간할 필드(the interpolated field)의 전후 필드들의 같은 샘플링 관계인 존재하는 스캔 라인(the existing scan line)들 사이에서만 움직임 추정이 이루어지므로 구현이 용이하다. 이때 구해진 움직임 벡터는 양방향 움직임 추정을 위한 초기 값으로 사용되어 진다. 제안한 알고리듬은 기존의 움직임 정보를 이용한 기법에 비해 구현이 용이하며, 카메라 움직임이 있는 panning, zooming 영상에 특히 효율적이다.

• The KIPS Transactions:PartB
• /
• v.10B no.3
• /
• pp.305-310
• /
• 2003

In this paper we deal with the system design and development of the high-speed automatic precision inspection for the defects of bolts. In order to inspect bolts continuously, we used the conveyor system. Also, this conveyor includes the servo motor and encoder to achieve accurate movement. According to encoder signal, line-scan camera captures the line-by-line image of bolts and after one frame is accumulated, various parameters are calculated and inspected by image processing algorithms. Experimental results using the developed facilities are presented to demonstrate the efficiency of the proposed equipment.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.43 no.1 s.307
• /
• pp.9-16
• /
• 2006

This Paper proposes an adaptive error diffusioThis paper proposes an adaptive error diffusion algorithm for text enhancement followed by an efficient text segmentation that uses the maximum gradient difference (MGD). The gradients are calculated along with scan lines, and the MGD values are filled within a local window to merge the potential text segments. Isolated segments are then eliminated in the non-text region filtering process. After the left segmentation, a conventional error diffusion method is applied to the background, while the edge enhancement error diffusion is used for the text. Since it is inevitable that visually objectionable artifacts are generated when using two different halftoning algorithms, the gradual dilation is proposed to minimize the boundary artifacts in the segmented text blocks before halftoning. Sharpening based on the gradually dilated text region (GDTR) prevents the printing of successive dots around the text region boundaries. The error diffusion algorithm with edge enhancement is extended to halftone color images to sharpen the tort regions. The proposed adaptive error diffusion algorithm involves color halftoning that controls the amount of edge enhancement using a general error filter. The multiplicative edge enhancement parameters are selected based on the amount of edge sharpening and color difference. Plus, the additional error factor is introduced to reduce the dot elimination artifact generated by the edge enhancement error diffusion. By using the proposed algorithm, the text of a scanned image is sharper than that with a conventional error diffusion without changing background.