The ability to change illumination is a crucial factor in image-based modeling and rendering. Image-based relighting offers such capability. However, the tradeoff is the enormous increase of storage ...requirement. In this paper, we propose a compression scheme that effectively reduces the data volume while maintaining the real-time relighting capability. The proposed method is based on principal component analysis (PCA). A block-wise PCA is used to practically process the huge input data. The output of PCA is a set of eigenimages and the corresponding relighting coefficients. By dropping those low-energy eigenimages, the data size is drastically reduced. To further compress the data, eigenimages left are compressed using transform coding and quantization while the relighting coefficients are compressed using uniform quantization. We also suggest the suitable target bit rate for each phase of the compression method in order to preserve the visual quality. Finally, we propose a real-time engine that relights images from the compressed data.
PCA-based compression for image-based relighting Pun-Mo Ho; Tien-Tsin Wong; Kwok-Hung Choy ...
2003 International Conference on Multimedia and Expo. ICME '03. Proceedings (Cat. No.03TH8698),
2003, Volume:
1
Conference Proceeding
The ability to change illumination is a crucial factor in image-based modeling and rendering. Image-based relighting offers such capability. However, the trade-off is the enormous increase of storage ...requirement. In this paper, we propose a compression scheme that effectively reduces the data volume while maintaining the real-time relighting capability. The proposed method is based on principal component analysis (PCA). A block-wise PCA is used to practically process the huge input data. The output of PCA is a set of eigenimages and the corresponding relighting coefficients. By dropping those low-energy eigenimages, the data size is drastically reduced. To further compress the data, eigenimages left are compressed using transform coding and quantization while the relighting coefficients are compressed using uniform quantization. We also suggest the suitable target bit rate for each phase of the compression method in order to preserve the visual quality. Finally, we propose real-time engine that relights images from the compressed data.
A maximum likelihood estimator (MLE) that jointly estimates the carrier frequency offset (CFO) and the channel response of each user in uplink OFDMA systems is investigated in this research. The ...proposed MLE distinguishes itself from existing methods by its applicability to more flexible carrier assignment schemes. It achieves high computational efficiency by transforming a multidimensional optimization problem into a one-dimensional optimization problem. A suboptimal method is developed to further reduce the computational complexity. It is demonstrated by simulation results that the proposed MLE can provide accurate CFO and channel estimation in both SISO and SIMO environments.
Single-agent doxorubicin has been widely used to treat unresectable hepatocellular carcinoma (HCC), but the response rate is low (< 20%) and there is no convincing evidence for improved survival. ...Cisplatin, interferon, doxorubicin, and fluorouracil (PIAF) used in combination, by contrast, has shown promise in a phase II study. We compared doxorubicin to PIAF in patients with unresectable HCC in a phase III trial.
Patients with histologically confirmed unresectable HCC were randomly assigned to receive either doxorubicin or PIAF every 3 weeks, for up to six cycles. The primary endpoint was overall survival, and secondary endpoints were response rate and toxicity. Survival differences were calculated using the Kaplan-Meier method. Treatment groups were compared for differences in the incidence of adverse events using chi-square tests. All statistical tests were two-sided.
The median survival of the doxorubicin and PIAF groups was 6.83 months (95% confidence CI = 4.80 to 9.56) and 8.67 months (95% CI = 6.36 to 12.00), respectively (P = 0.83). The hazard ratio for death from any cause in the PIAF compared with the doxorubicin groups was 0.97 (95% CI = 0.71 to 1.32). Eighty-six of the 94 patients receiving doxorubicin and 91 of the 94 receiving PIAF were assessable for response. The overall response rates in the doxorubicin and PIAF groups were 10.5% (95% CI = 3.9% to 16.9%) and 20.9% (95% CI = 12.5% to 29.2%), respectively. Neutropenia, thrombocytopenia, and hypokalemia were statistically significantly more common in patients treated with PIAF than in patients treated with doxorubicin.
Although patients on PIAF had a higher overall response rate and better survival than patients on doxorubicin, the differences were not statistically significant. PIAF was also associated with increased treatment-related toxicity. The prognosis of patients with unresectable HCC remains poor.
To compare effectiveness of transarterial ethanol ablation (TEA) and transcatheter arterial chemoembolization (TACE) for unresectable hepatocellular carcinoma and determine whether TEA leads to ...better overall survival and tumor response than TACE.
In this institutional review board-approved preregistered randomized controlled trial (n = 200), informed consent was obtained. Primary outcome was overall survival; secondary outcomes were time to progression (TTP), progression-free survival (PFS), tumor response at computed tomography, and treatment-related toxicity. Eligible patients were randomized at a 1:1 ratio. Treatment included transcatheter delivery of ethiodized oil-ethanol mixture (2:1 ratio by volume up to 60 mL) for TEA and cisplatin-ethiodized oil emulsion (0.5 mg cisplatin per milliliter up to 30 mg), followed by 1-mm gelatin-sponge pellets, for TACE. Study was terminated after interim analysis (n = 98); 90 patients were available for analysis. Overall survival, TTP, and PFS were analyzed with Kaplan-Meier method; differences were compared with log-rank test.
Study was terminated prematurely after interim analysis, which showed no difference in overall survival; this was unlikely to change with further patient accrual. Median overall survival in TEA and TACE was 24.3 months (95% confidence interval CI: 12.8, 32.7) and 20.1 months (95% CI: 9.3, 31.2), respectively (P = .358). Median TTP and PFS for intralesional progression were longer with TEA than TACE (TTP, 34.6 months 95% CI: 28.2, 41 vs 26.05 months 95% CI: 18.7, 33.3; PFS, 14.8 months 95% CI: 10.2, 19.5 vs 9.3 months 95% CI: 7.1, 11.5) (P = .028 and 0.029, respectively). Complete response rate on a tumor basis was persistently and significantly higher with TEA at 3 months (62 of 88 70% vs 39 of 76 51%, P = .012), 6 months (64 of 88 73% vs 41 of 76 54%, P = .012), and 12 months (66 of 88 75% vs 45 of 76 59%, P = .031).
Although there was no significant difference in overall survival, TEA demonstrated better complete tumor response, longer time to intralesional progression, and longer PFS.
Background: Single-agent doxorubicin has been widely used to treat unresectable hepatocellular carcinoma (HCC), but the response rate is low (<20%) and there is no convincing evidence for improved ...survival. Cisplatin, interferon, doxorubicin, and fluorouracil (PIAF) used in combination, by contrast, has shown promise in a phase II study. We compared doxorubicin to PIAF in patients with unresectable HCC in a phase III trial. Methods: Patients with histologically confirmed unresectable HCC were randomly assigned to receive either doxorubicin or PIAF every 3 weeks, for up to six cycles. The primary endpoint was overall survival, and secondary endpoints were response rate and toxicity. Survival differences were calculated using the Kaplan-Meier method. Treatment groups were compared for differences in the incidence of adverse events using chi-square tests. All statistical tests were two-sided. Results: The median survival of the doxorubicin and PIAF groups was 6.83 months (95% confidence CI = 4.80 to 9.56) and 8.67 months (95% CI = 6.36 to 12.00), respectively (P = 0.83). The hazard ratio for death from any cause in the PIAF compared with the doxorubicin groups was 0.97 (95% CI = 0.71 to 1.32). Eighty-six of the 94 patients receiving doxorubicin and 91 of the 94 receiving PIAF were assessable for response. The overall response rates in the doxorubicin and PIAF groups were 10.5% (95% CI = 3.9% to 16.9%) and 20.9% (95% CI = 12.5% to 29.2%), respectively. Neutropenia, thrombocytopenia, and hypokalemia were statistically significantly more common in patients treated with PIAF than in patients treated with doxorubicin. Conclusion: Although patients on PIAF had a higher overall response rate and better survival than patients on doxorubicin, the differences were not statistically significant. PIAF was also associated with increased treatment-related toxicity. The prognosis of patients with unresectable HCC remains poor.
HCC is a common cause of morbidity and mortality. For patients who are not candidates for curative surgery, systemic chemotherapy is one of the standard treatments. In parts of China and the Far ...East, over 80% of HCC patients have chronic HBV infection. In this study, we aimed to assess the relationship between pre‐chemotherapy HBV viral load and the survival of HCC patients. HBV infection status was determined prior to chemotherapy in 188 patients, 170 of whom had evidence of HBV chronic infection/exposure (160 hepatitis B surface antigen HBsAg‐positive, 10 HBsAg‐negative/hepatitis B core antibody–positive). Of these, 125 had pretreatment HBV DNA levels determined via real‐time PCR. Virological data were analyzed using conventional clinical variables to identify factors that influenced survival. Multivariate analysis revealed that high total bilirubin (P = 0.0016; hazard ratio = 1.040 per 1 μM increase; 95% CI 1.015–1.065), HCV infection (P = 0.0095; hazard ratio = 6.955; 95% CI 1.606–30.129), and high HBV DNA level (P = 0.0217; hazard ratio = 1.650; 95% CI 1.076–2.531) affected survival significantly. Exploratory analysis revealed that high levels of pretreatment HBV DNA had a significantly higher incidence of severe hepatitis during chemotherapy. Conclusion: For HCC patients with HBV chronic infection/exposure, a high viral load prior to treatment is an adverse factor for survival and may be associated with a higher incidence of severe hepatitis during chemotherapy. Future strategies to improve the prognosis of HCC patients undergoing chemotherapy should consider supportive therapy that incorporates antiviral therapies to reduce HBV viral load. (HEPATOLOGY 2007;45:1382–1389.)
: TT virus (TTV) is a recently described circular DNA virus of about 3.8 kb, which is related to the circoviridae viruses. It is commonly detected in healthy subjects and no association with any ...specific disease has been established. TTV was initially thought to be hepatotropic, but subsequent reports have shown that it is detectable in other tissues, including kidney, prostate, mammary gland, brain, bone marrow, and peripheral blood mononuclear cells. Plasma samples from cancer patients and healthy subjects were tested for the presence or absence of TTV by heminested polymerase chain reaction (PCR). We also developed a quantitative competitive PCR (QC‐PCR) assay for TTV that permits accurate measurement of TTV DNA load. Using this assay, the TTV genome load in peripheral blood mononuclear cells (PBMCs) of healthy control subjects (n= 50) and patients with various types of cancer (n= 148), including breast cancer, non‐Hodgkin's lymphoma, colon cancer, hepatocellular carcinoma, nasopharyngeal carcinoma, and other cancers, was measured. TTV DNA was detected in 69 of 100 plasma samples (69%) of cancer patients tested and in 39 of 100 plasma samples (39%) randomly selected from 1000 plasma samples of blood donors (p < 0.05). TTV DNA was detectable in the PBMCs of 99% of the cancer patients and 86% of the controls. However, the median virus load was more than 100‐fold higher in the cancer patients (3599 copies/100,000 cells) than among the controls (30 copies/100,000 cells; p < 0.0001). There was no significant difference in TTV load among the different cancer types. Using a cutoff value of >250 copies per 100,000 PBMCs, 93.2% of cancer patients were “positive” compared to only 4% of healthy control subjects. Almost all the cancer patients have TTV infection and their TTV genome load in PBMCs is significantly higher than that in control subjects. It remains to be elucidated whether such findings are specific to cancer patients or occur in all seriously ill subjects.
TT virus (TTV) is a recently described circular DNA virus of about 3.8 kb, which is related to the Circoviridae viruses. It is commonly detected in healthy subjects and no association with any ...specific disease has been established. TTV was initially thought to be hepatotropic, but subsequent reports have shown that it is detectable in other tissues, including kidney, prostate, mammary gland, brain, bone marrow, and peripheral blood mononuclear cells. Plasma samples from cancer patients and healthy subjects were tested for the presence or absence of TTV by heminested polymerase chain reaction (PCR). We also developed a quantitative competitive PCR (QC-PCR) assay for TTV that permits accurate measurement of TTV DNA load. Using this assay, the TTV genome load in peripheral blood mononuclear cells (PBMCs) of healthy control subjects (n = 50) and patients with various types of cancer (n = 148), including breast cancer, non-Hodgkin's lymphoma, colon cancer, hepatocellular carcinoma, nasopharyngeal carcinoma, and other cancers, was measured. TTV DNA was detected in 69 of 100 plasma samples (69%) of cancer patients tested and in 39 of 100 plasma samples (39%) randomly selected from 1000 plasma samples of blood donors (p < 0.05). TTV DNA was detectable in the PBMCs of 99% of the cancer patients and 86% of the controls. However, the median virus load was more than 100-fold higher in the cancer patients (3599 copies/100,000 cells) than among the controls (30 copies/100,000 cells; p < 0.0001). There was no significant difference in TTV load among the different cancer types. Using a cutoff value of >250 copies per 100,000 PBMCs, 93.2% of cancer patients were "positive" compared to only 4% of healthy control subjects. Almost all the cancer patients have TTV infection and their TTV genome load in PBMCs is significantly higher than that in control subjects. It remains to be elucidated whether such findings are specific to cancer patients or occur in all seriously ill subjects.
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