• Journal of Korea Multimedia Society
• /
• v.9 no.8
• /
• pp.971-981
• /
• 2006

As shear-warp volume rendering is the fastest rendering method among the software based approaches, image quality is not good as that of other high-quality rendering methods. In this paper, we propose two methods to improve the image quality of shear-warp volume rendering without sacrificing computational efficiency. First, supersampling is performed in intermediate image space. We propose an efficient method to transform between volume and image coordinates at the arbitrary ratio. Second, we utilize pre-integrated rendering technique for shear-warp rendering. We propose new data structure called overlapped min-max map. Using this structure, empty space leaping can be performed so that we can maintain the rendering speed even though pre-integrated rendering is applied. Consequently, shear-warp rendering can generate high-qualify images comparable to those generated by the ray-casting without degrading speed.

• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.3_4
• /
• pp.187-194
• /
• 2004

Shear-Warp volume rendering has many advantages such as good image Quality and fast rendering speed. However in the interactive classification environment it has low efficiency of memory access since preprocessed classification is unavailable. In this paper we present an algorithm using the spacial locality of memory access in the interactive classification environment. We propose an extension model appending a rotation matrix to the factorization of viewing transformation, it thus performs a scanline-based rendering in the object and image space. We also show causes and solutions of three problems of the proposed algorithm such as inaccurate front-to-back composition, existence of hole, increasing computational cost. This model is efficient due to the spacial locality of memory access.

• Journal of Biomedical Engineering Research
• /
• v.21 no.4
• /
• pp.433-439
• /
• 2000

Volume rendering is a powerful tool for visualizing sampled scalar values from 3D data without modeling geometric primitives to the data. The volume rendering can describe the surface-detail of a complex object. Owing to this characteristic. volume rendering has been used to visualize medical data. The size of volume data is usually too big to handle in real time. Recently, various volume rendering algorithms have been proposed in order to reduce the rendering time. However, most of the proposed algorithms are not proper for fast rendering of large non-coded volume data. In this paper, we propose a block-based fast volume rendering algorithm using a shear-warp factorization for non-coded volume data. The algorithm performs volume rendering by using the organ segmentation data as well as block-based 3D volume data, and increases the rendering speed for large non-coded volume data. The proposed algorithm is evaluated by rendering 3D X-ray CT body images and MR head images.

• Journal of Korea Multimedia Society
• /
• v.12 no.4
• /
• pp.512-520
• /
• 2009

Maximum intensity projection (MIP) is a volume rendering method which extracts maximum values along the viewing direction through volume data. It visualizes high-density structures, such as angio-graphic datasets so that it is frequently used in medical imaging systems. We have proposed an efficient two-step MIP acceleration method that uses the recent CPUs. First, we exploited SIMD instructions to reduce conditional branch instructions which take up a considerable part of whole rendering process, so that we improved rendering speed. Second, we proposed a new method, which accesses volume and image data successively by modifying the shear-warp rendering. This method improves memory access patterns so that cache misses are reduced. Using the current CPUs, our method improved the rendering speed by a factor of 7 than that of the shear-warp rendering.