pali3 0.0.3

pali3 - Pytorch

Pali3

"Figure 1: Overview of the PaLI-3 (5B) model: images are encoded into visual tokens individually by the contrastively pretrained 2B SigLIP vision model. Along with a query, these visual tokens are passed to an 3B encoder-decoder UL2 Transformer which produces the desired answer."

Vit trained with siglip loss -> embeddings -> ul2 -> text tokens

text -> tokenizer -> embeddings -> ul2 -> text tokens

Installation

pip install pali3

Usage:

Architecture

Here is the ASCII representation of the model architecture and the stages of training:

Model Architecture:

Image Input
    |
    V
Contrastive Vision Encoder (ViT-G/14)
    |
    V
Transformer Encoder
    |
    V
Transformer Decoder
    |
    V
Text Output

Stages of Training:

Stage 0: Unimodal pretraining
    |
    V
Stage 1: Multimodal training
    |
    V
Stage 2: Resolution increase
    |
    V
Task specialization (transfer)

The model architecture consists of a contrastive vision encoder (ViT-G/14) that encodes the image into tokens. These tokens are passed to a transformer encoder and then to a transformer decoder that generates a text output.

The training procedure consists of multiple stages:

• Stage 0: Unimodal pretraining. The image encoder is pretrained contrastively on image-text pairs from the web, following the SigLIP training protocol. The text encoder-decoder is a 3B UL2 model trained following the mixture of denoisers procedure.

• Stage 1: Multimodal training. The image encoder is combined with the text encoder-decoder and trained on a multimodal task and data mixture, keeping the image encoder frozen and using its native resolution.

• Stage 2: Resolution increase. The resolution of the model is increased by fine-tuning the whole model with a short curriculum of increasing resolutions.

• Task specialization (transfer). Finally, for each individual task, the model is fine-tuned with frozen ViT image encoder on the task's training data.

Please note that this is a high-level representation and the actual implementation might involve more details and complexities.

License

MIT

Todo

• Implement sig_lip vit model with training recipe
• Implement the text tokenizer, maybe use token monster
• Implement the UL2 Transformer Encoder and Decoder
• Implement training scripts for the full pali3 model