130 research outputs found
Real-time Controllable Denoising for Image and Video
Controllable image denoising aims to generate clean samples with human
perceptual priors and balance sharpness and smoothness. In traditional
filter-based denoising methods, this can be easily achieved by adjusting the
filtering strength. However, for NN (Neural Network)-based models, adjusting
the final denoising strength requires performing network inference each time,
making it almost impossible for real-time user interaction. In this paper, we
introduce Real-time Controllable Denoising (RCD), the first deep image and
video denoising pipeline that provides a fully controllable user interface to
edit arbitrary denoising levels in real-time with only one-time network
inference. Unlike existing controllable denoising methods that require multiple
denoisers and training stages, RCD replaces the last output layer (which
usually outputs a single noise map) of an existing CNN-based model with a
lightweight module that outputs multiple noise maps. We propose a novel Noise
Decorrelation process to enforce the orthogonality of the noise feature maps,
allowing arbitrary noise level control through noise map interpolation. This
process is network-free and does not require network inference. Our experiments
show that RCD can enable real-time editable image and video denoising for
various existing heavy-weight models without sacrificing their original
performance.Comment: CVPR 202
DiffusionMat: Alpha Matting as Sequential Refinement Learning
In this paper, we introduce DiffusionMat, a novel image matting framework
that employs a diffusion model for the transition from coarse to refined alpha
mattes. Diverging from conventional methods that utilize trimaps merely as
loose guidance for alpha matte prediction, our approach treats image matting as
a sequential refinement learning process. This process begins with the addition
of noise to trimaps and iteratively denoises them using a pre-trained diffusion
model, which incrementally guides the prediction towards a clean alpha matte.
The key innovation of our framework is a correction module that adjusts the
output at each denoising step, ensuring that the final result is consistent
with the input image's structures. We also introduce the Alpha Reliability
Propagation, a novel technique designed to maximize the utility of available
guidance by selectively enhancing the trimap regions with confident alpha
information, thus simplifying the correction task. To train the correction
module, we devise specialized loss functions that target the accuracy of the
alpha matte's edges and the consistency of its opaque and transparent regions.
We evaluate our model across several image matting benchmarks, and the results
indicate that DiffusionMat consistently outperforms existing methods. Project
page at~\url{https://cnnlstm.github.io/DiffusionMa
Oxy-coal combustion in a 30kWth pressurized fluidized bed: Effect of combustion pressure on combustion performance, pollutant emissions and desulfurization
Oxy-coal combustion with pressurized fluidized beds has recently emerged as a promising carbon capture and storage (CCS) technology for coal-fired power plants. Although a large number of energy efficiency analyses have shown that an increase in combustion pressure can further increase the net plant efficiency, there are few experimental studies of pressurized oxy-coal combustion conducted on fluidized bed combustors/boilers with continuous coal feeding. In this study, oxy-coal combustion experiments with lignite and anthracite were conducted with a 30 kWth pressurized fluidized bed combustor within the pressure range of 0.1 MPa to 0.4 MPa. The investigation focused on the elucidation of the impacts of combustion pressure on the combustion performance, pollutant emissions and desulfurization of oxy-coal combustion in fluidized beds. The results showed that an increase in pressure increased the combustion efficiency and combustion rate of coal particles, and the promoting effect of pressure increase was more significant for the high rank coal with smaller particle size and the high O2 concentration atmosphere. For both coals, NOx emissions decreased with pressure but N2O emissions increased with pressure and accounted for a considerable part of the nitrogen oxide pollutants under high pressure oxy-coal combustion conditions. The pressure had insignificant impact on the SO2 emissions of oxy-coal combustion but an increase in pressure enhanced the direct desulfurization of limestone
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