Cosmos-Tokenize1: A suite of image and video tokenizers

Cosmos | Code | Paper | Paper Website

Model Overview

Description:

Cosmos-Tokenize1 is a suite of visual tokenizers for images and videos that delivers various compression rates while maintaining high reconstruction quality. Cosmos Tokenizer can serve as an effective and efficient building block in both diffusion-based and autoregressive models for image and video generation. This model is ready for commercial use.

Our tokenizers come in two types: Continuous (C) and Discrete (D), each with Image (I) and Video (V) variants:

• Continuous tokenizers encode visual data into continuous latent embeddings, as shown in latent diffusion models like Stable Diffusion. These embeddings are suitable for models that generate data by sampling from continuous distributions.
• Discrete tokenizers encode visual data into discrete latent codes, mapping them into quantized indices, as seen in autoregressive transformers such as VideoPoet. This discretization is required for models that generate data by optimizing the cross-entropy loss, such as the GPT models.

Model: Cosmos-Tokenize1-DV8x16x16-720p, a discrete video tokenizer with 8x temporal compression, and 16x16 spatial compression rate.

Model Developer: NVIDIA

Model Versions

The Cosmos-Tokenize1 includes the following tokenizers:

• Continuous Tokenizers

  • Cosmos-Tokenize1-CI8x8-360p (8x8 spatial compression, 360p and above)
  • Cosmos-Tokenize1-CI16x16-360p (16x16 spatial compression, 360p and above)
  • Cosmos-Tokenize1-CV4x8x8-360p (4x temporal compression, 8x8 spatial compression, 360p and above, 49 frames context)
  • Cosmos-Tokenize1-CV8x8x8-720p (8x temporal compression, 8x8 spatial compression, 720p and above, 121 frames context)

• Discrete Tokenizers

  • Cosmos-Tokenize1-DI8x8-360p (8x8 spatial compression, 360p and above)
  • Cosmos-Tokenize1-DI16x16-360p (16x16 spatial compression, 360p and above)
  • Cosmos-Tokenize1-DV4x8x8-360p (4x temporal compression, 8x8 spatial compression, 360p and above, 49 frames context)
  • Cosmos-Tokenize1-DV8x16x16-720p (8x temporal compression, 16x16 spatial compression, 720p and above, 49 frames context)

License:

This model is released under the NVIDIA Open Model License. For a custom license, please contact cosmos-license@nvidia.com.

Under the NVIDIA Open Model License, NVIDIA confirms:

• Models are commercially usable.
• You are free to create and distribute Derivative Models.
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Model Architecture:

Cosmos-Tokenize1-DV8x16x16-720p is a lightweight and computationally efficient architecture, featuring a temporally causal design. Specifically, we employ causal temporal convolution and causal temporal attention layers to preserve the natural temporal order of video frames, ensuring seamless tokenization of images and videos using a single unified network architecture. The encoder and decoder form a symmetrical pair, which are mirrors of each other. The encoder starts with a 2-level Haar wavelet transform layer, which down-samples inputs by a factor of 4 in both spatial and temporal dimensions. Likewise, the decoder ends with an inverse wavelet transform. We employ the vanilla autoencoder (AE) formulation to model the latent space for continuous tokenizers. For discrete tokenizers, we adopt the Finite-Scalar-Quantization (FSQ) as the latent space quantizer.

Input/Output Specifications

Encoder

• Input

  • Type: Images or Videos
  • Format: RGB (Red, Green, Blue)
  • Properties:
    • Resolution: Minimum: 256px (shorter side). Maximum: Up to 4K
    • Video Length: Up to 8 seconds for 1080p videos (bounded by A100 80G GPU memory; higher resolutions will have shorter supported durations)

• Output

  • Type: Tokens
  • Properties:
    • Integer indices ranging from 0 to 63,999

Decoder

• Input

  • Type: Tokens
  • Properties:
    • Integer indices ranging from 0 to 63,999

• Output

  • Type Images or Videos (matching input type)
  • Format: RGB (Red, Green, Blue)
  • Properties:
    • Resolution: Same as input resolution
    • Video Length: Same as input video length

Software Integration (Required For NVIDIA Models Only):

Runtime Engine(s):

• Cosmos-Predict1

Supported Hardware Microarchitecture Compatibility:

• NVIDIA Ampere (e.g., A100)
• NVIDIA Hopper (e.g., H100)

Note: We have only tested Cosmos Tokenizer with BF16 precision on Ampere and Hopper GPUs. If you are using older versions of NVIDIA GPUs (e.g., NVIDIA Volta GPUs), you may need to switch to FP32 precision.

Operating System(s):

• Linux (We have not tested on other operating systems.)

Usage

Inference Engines:

• See Cosmos-Predict1 (PyTorch) for details.

Evaluation

Tokenization Comparison

We have extensively evaluated the additional Cosmos Tokenizer models on DAVIS video benchmark dataset.

• We compare with the state-of-the-art discrete video tokenizer, OmniTokenizer.
• Evaluation metrics:
  • Peak Signal-to-Noise Ratio (PSNR)
  • Structural Similarity (SSIM)
  • Reconstruction Fréchet Video Distance (rFVD)

Runtime Comparison

The following table shows the number of parameters and the averaged encoding and decoding times per image or video frame, measured on a single A100 80GB GPU. For comparison, we also list the parameters and average speeds of prior state-of-the-art tokenizer(s) with the same compression ratio.

Note: We benchmarked the runtime for images under the 8x8 compression and videos under the 4×8×8 compression. Tokenizers with different compression ratios are not included in this comparison.

Ethical Considerations

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• Reviewed before release.
• Tagged for known restrictions and potential safety implications.

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