提出新损失函数,让压缩模型自动优化上下文信息以提升效率。
Causal Context Adjustment Loss for Learned Image Compression
- 用新损失函数引导网络主动调整解码上下文
- 在保持高画质的同时降低推理延迟
- 适合追求高效图像压缩的开发者
近年来,学习型图像压缩(LIC)在率失真(RD)性能上显著超越传统方法。现有方法多基于变分自编码器(VAE),并采用自回归熵模型,通过利用解码的因果上下文提升了性能。然而,这些方法高度依赖固定的手工设计上下文,如何引导自编码器生成对自回归熵模型更有效的上下文仍值得探索。本文首次提出因果上下文调整损失(CCA-loss),通过施加该损失,使神经网络能够自发地将关键信息注入自回归熵模型的早期阶段。此外,随着Transformer技术的发展,许多SOTA LIC方法已采用其变体,但现有计算设备对注意力机制计算支持不佳,导致计算量大、推理延迟高。为此,我们构建了一个基于卷积神经网络(CNN)的图像压缩模型,并采用非均匀通道分组策略以提高效率。最终,使用CCA-loss训练的CNN-based LIC网络在推理延迟与率失真性能之间取得了优异平衡。
原文摘要 · Abstract (English)
In recent years, learned image compression (LIC) technologies have surpassed conventional methods notably in terms of rate-distortion (RD) performance. Most present learned techniques are VAE-based with an autoregressive entropy model, which obviously promotes the RD performance by utilizing the decoded causal context. However, extant methods are highly dependent on the fixed hand-crafted causal context. The question of how to guide the auto-encoder to generate a more effective causal context benefit for the autoregressive entropy models is worth exploring. In this paper, we make the first attempt in investigating the way to explicitly adjust the causal context with our proposed Causal Context Adjustment loss (CCA-loss). By imposing the CCA-loss, we enable the neural network to spontaneously adjust important information into the early stage of the autoregressive entropy model. Furthermore, as transformer technology develops remarkably, variants of which have been adopted by many state-of-the-art (SOTA) LIC techniques. The existing computing devices have not adapted the calculation of the attention mechanism well, which leads to a burden on computation quantity and inference latency. To overcome it, we establish a convolutional neural network (CNN) image compression model and adopt the unevenly channel-wise grouped strategy for high efficiency. Ultimately, the proposed CNN-based LIC network trained with our Causal Context Adjustment loss attains a great trade-off between inference latency and rate-distortion performance.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。