3D geometry-dependent texture map compression with a hybrid ROI coding

Region of interest (ROI) coding is a mechanism deployed in several image coding systems to enable different degrees of coding priority to specific regions of the image. JPEG2000 standard provides two ROI coding methods. However, both of them are based in mechanisms that scale the quantized coefficients. This compels to encode the additional bit-planes needed for the scaling, causing a penalization in the overall coding performance, and the ROIs can not be modified without a complete re-encoding of the image. This paper introduces two ROI coding methods that use rate-distortion optimization techniques to prioritize arbitrary ROIs over the rest of the image without penalizing the overall coding performance. Experimental results suggest that the proposed methods achieve a close to optimal accuracy, improving the Implicit ROI coding method in terms of ROI rate distortion performance.

Three-dimensional wavelet coding of volumetric medical images provides better coding performance compared to corresponding 2D methods by exploiting the inter-slice correlation that exists in such data. It introduces however latencies when it comes to retrieving/transmitting specific parts of the volume. This paper presents an extension to 3D-SPIHT which allows 3D region of interest (ROI) coding. ROI coding enables faster reconstruction of diagnostically useful regions in volumetric datasets by assigning higher priority to them in the bitstream. It also introduces the possibility for an increased compression performance, by allowing certain parts of the image to be coded in a lossy manner while others are coded losslessly. The necessary modifications to 3D-SPIHT for ROI coding are described and methods for specifying a 3D ROI without adding a significant overhead are suggested. Results are presented highlighting the benefits of the ROI extension.

Multiple Region of Interest (ROI) coding is important in applications where some parts of the image are of higher importance than others and need to be encoded at higher quality than the background. The new image coding standard JPEG2000 recommended the Maxshift method to complete ROI coding. However, the drawback of the Maxshift method is that the coefficient bitplanes of all ROIs must be scaled with the same values, which cannot code ROIs according to different degrees of interest. This paper describes a flexible multiple ROI coding scheme called BTShift (Bitplane Twice Shift). The proposed method uses different bitplane scaling strategies between low frequency subbands and high frequency subbands. Experimental results on several state-of-the-art images show that the new scheme does not only support multiple ROI coding according to different degrees of interest, but also can encode the ROIs and background without their shape information. Additionally, BTShift is compliant with the recommended Maxshift method. So we hope the proposed method can be valuable for the remote sensing image compression and medical image coding in the future.

A compression scheme for calibrated images depicting a static scene from arbitrary viewpoints is presented. 3D scene geometry is reconstructed, and view-dependent texture maps are generated from all images. Texture is wavelet-coded using the SPIHT coding scheme extended to 4D, exploiting correlations within as well as between texture maps. During decoding, all texture maps are simultaneously and progressively reconstructed. The coder provides 3D scene geometry and multiple texture maps, enabling the use of graphics hardware to accelerate the rendering process. Three image sets acquired from real-world objects are used to evaluate the model-based coding scheme. Coding efficiency is shown for geometry approximations of different accuracy.

This paper describes a method of producing scenes for TV programs, using “dynamic 3D human models.” Dynamic 3D human models are 3D models generated from images shot by multiple cameras surrounding an actor for each frame using 3D-reconstruction and texture-mapping techniques. They can provide highly realistic images as well as natural motions without having to use a motion-capture system. In addition, they allow production to be more flexible, enabling the positions of models to be changed or multiplying the amount used. Dynamic 3D human models are therefore suitable for producing crowd scenes. Although techniques of 3D reconstruction and texture mapping have been discussed and several applications have been proposed, they have not been widely introduced into TV or movie production, because of the huge amounts of data and insufficient textural quality. By establishing an efficient production flow with recent powerful computers and 24 HD cameras, the authors succeeded in producing crowd scenes with sufficient quality for a TV program, which will be aired in December 2009. The scenes involving 1,000 soldiers can be produced by shooting several sequences with two actors. The production flow that was established is described as well as scenes that were produced using dynamic 3D human models for a drama.

Summary form only given. Normally, image data have important details in only some regions. One feature of JPEG2000 still image coding is the ability to code a region of interest (ROI) with higher quality. The standard defines two methods for ROI coding, generic shift and maximum bitplane shift (maxshift). Generic shift can select the scaling value of the ROI, but the shape needs to be sent to the decoder, whereas maxshift does not need to send it. However, maxshift does not allow the selection of a scaling value to define the relative importance between ROI and background (BG) coefficients. Later, BbB shift and GBbB shift were proposed. These two methods can select the scaling value without the need to send shape information, but these two methods are not applicable for multiple ROI coding. Lately, the partial significant bitplane (PSB) shift was proposed. It offers different degrees of interest and also supports multiple ROI coding. However, PSB shift sacrifices some qualities of ROI in exchange for the improved quality of the BG region. To some extent, it causes the ROI to be coded at lesser quality than the BG. We analyze the advantages and disadvantages of each method and propose the use of PSB shift in conjunction with the maxshift scheme to achieve better quality in the ROI with the ability to adjust the degree of interest relative to its importance.

It takes a long time for the users to view a whole image from the image server under the low-bandwidth internet environments or in case of a big sized image. In this case, as there needs a technique that preferentially transfers a part of image, JPEG2000 offers a ROI(Region-of-Interest) coding. In ROI coding, the users see the thumbnail of image from the server and specifies some regions that they want to see first. And then if an information about the regions are informed to the server, the server preferentially transfers the regions of the image. The existing methods requested a huge time to compute the mask information, but this thesis approximately computes the regions and reduces the creating time of the ROI masks. If each code block is a mixed block which ROI and background are mixed, the proper boundary points should be acquired. Searching the edges of the block, getting the two points on the edge, to get the boundary point inside the code block, the method searches a mid point between the two edge points. The proposed method doesn`t have a big difference compared to the existing methods in quality, but the processing time is more speedy than the ones.

Regions of Interest (ROI) image coding enables the regions important to medical diagnosis to be encoded and transmitted at higher quality than the other regions. In the paper, a new ROI coding method called Compensation-based Partial Bitplane Alternating Shift (CPBA- Shift) is described. The proposed method divides all bitplanes of ROI and background (BG) coefficients into two portions-Alternating Shift Portion (ASP) and Compensation Shift Portion (CSP). In ASP, partial the most significant bitplanes of ROI and BG coefficients are shifted by bitplane-by-bitplane. In CSP, the least significant bitplanes of ROI and BG coefficients are scaled using compensation scheme according to the compression quality in ROI and BG. Simulation experiments show that the new method, in addition to alleviating the drawbacks of both ROI coding methods in JPEG2000, can support arbitrarily shaped multiple ROI coding with different degrees of interest without coding the shapes information.

Region of interest coding in JPEG 2000

In order to better display and protect ancient Chinese architecture, a three-dimensional model reconstruction method based on multi-station laser scanning is proposed. This method mainly includes several steps, such as point cloud data collection, preconditioning, multi-site cloud data fusion, point cloud data compression, 3D model reconstruction and texture mapping, environment rendering, video processing, and 3D roaming. According to the requirement of video rendering and virtual roaming, we focus on cloud processing, 3D modeling and 3D model display in this paper. Experimental results show that an famous building named Enshi Dong Drum Tower is well digitally reconstructed, so as to result in ethnic characteristics and cultural heritage protection in practical application.

This paper describes a method of producing scenes for TV program, using “dynamic 3D models”. Dynamic 3D models are 3D models generated from images shot by multiple cameras surrounding an actor for each frame using 3D-reconstruction and texture-mapping techniques. They can provide highly realistic images as well as natural motion without using a motion-capture system. In addition, they allow flexible production, so the positions of the models can be changed and the models can be duplicated. Dynamic 3D models are therefore suitable for producing crowd scenes with numerous people. Although techniques of 3D reconstruction and texture mapping have been discussed and several applications have been proposed, they have not been widely used into TV or movie production because of the size of data and insufficient textural quality. By establishing an efficient production flow with recent powerful processors, we succeeded in producing scenes with sufficient quality for a TV program, which was aired in December, 2009. The scenes involving one thousand soldiers could be produced by shooting several sequences with only two actors. We describe the production flow that we established and present some scenes that we produced using dynamic 3D models for the drama.

Given the technical requirements for equipment storage in the power industry, conventional storage methods prove inadequate for managing specialized materials such as precision instruments. To address texture distortion and detail loss in 3D visualization of such equipment, this study establishes a fused rendering algorithm integrating Dynamic Weighted Linear Interpolation (DWLI) and Adaptive Texture Mapping (ATM). The innovative contributions are threefold in several aspects. Firstly, we propose a Triple-Feature Descriptor (TFD) that categorizes surface characteristics across three orthogonal dimensions: geometric structure, material properties, and photometric attributes. This approach enhances feature discriminability by 32.7% compared to conventional methods. Secondly, our curvature-adaptive sampling strategy dynamically adjusts resolution (scalable from 256 × 256 to 1024 × 1024), improving edge fidelity in precision components (e.g., miniature relays) by 19.3 dB PSNR. Thirdly, the designed mapping architecture maintains color accuracy below ΔE < 3.2 across illuminance levels of 50-1000lx. Validation on the MDPI power warehouse dataset demonstrates 91.4% material identification accuracy with real-time rendering at 28 fps (RTX 3060). Deployment at a State Grid hub warehouse elevated sorting throughput by 40% and slashed manual verification workload by 65%. Comparative evaluations against conventional Texture Mapping methods reveal performance improvements exceeding 10% in both algorithm precision and recall rates. These advancements contribute substantially to operational efficiency in warehouse management systems, particularly facilitating cross-temporal domain material allocation optimization and resource coordination. The research outcomes provide practical solutions for addressing technical challenges in modern power industry logistics management.

Efficient 3D face reconstruction is very important for face animation and recognition. The slow speed of the 3D morphable model is due to the texture mapping. To improve the speed, we only use the shape matching to recover the 3D shape and use texture mapping to get the texture. However, only with the shape information, one image is not enough for accurate 3D face reconstruction. So, we propose to use multiple images with the morphable shape model. First, with the feature points given on the multiple images, the 3D coordinates of the feature points are estimate by the pose estimation. Then, frontal and profile 2D morphable shape models are built to estimate the 3D morphable shape model. These two steps works iteratively to improve the result. At last, the texture is extracted from multiple images with the pose estimation from the estimated 3D face. The effectiveness of our method is demonstrated by the experimental results.

Four dimensional image is 3D volume data that varies with time. It is used to express deforming or moving object in virtual surgery of 4D ultrasound. It is difficult to render 4D image by conventional ray-casting or shear-warp factorization methods because of their time-consuming rendering time or pre-processing stage whenever the volume data are changed. Even 3D texture mapping is used, repeated volume loading is also time-consuming in 4D image rendering. In this study, we propose a method to reduce data loading time using coherence between currently loaded volume and previously loaded volume in order to achieve real time rendering based on 3D texture mapping. Volume data are divided into small bricks and each brick being loaded is tested for similarity to one which was already loaded in memory. If the brick passed the test, it is defined as 3D texture by OpenGL functions. Later, the texture slices of the brick are mapped into polygons and blended by OpenGL blending functions. All bricks undergo this test. Continuously deforming fifty volumes are rendered in interactive time with SGI ONYX. Real-time volume rendering based on 3D texture mapping is currently available on PC.

Maximizing visual effect is a major problem in real-time animation. A real-time hair animation framework was proposed previously by C. K. Koh and Z. Huang (2000, 2001) based on 2D representation and texture mapping. One problem is that it lacks of the volumetric effect due to its 2D nature. This paper presents a technique using the U-shape strip to solve the problem.