ollama/model/models/gemma3/model_vision.go
2025-03-11 14:49:20 -07:00

128 lines
3.8 KiB
Go

package gemma3
import (
"math"
"github.com/ollama/ollama/ml"
"github.com/ollama/ollama/ml/nn"
)
var batchSize int = 1
type VisionSelfAttention struct {
Query *nn.Linear `gguf:"attn_q"`
Key *nn.Linear `gguf:"attn_k"`
Value *nn.Linear `gguf:"attn_v"`
Output *nn.Linear `gguf:"attn_output"`
}
func (sa *VisionSelfAttention) Forward(ctx ml.Context, hiddenState ml.Tensor, opts *VisionModelOptions) ml.Tensor {
headDim := opts.hiddenSize / opts.numHeads
query := sa.Query.Forward(ctx, hiddenState)
key := sa.Key.Forward(ctx, hiddenState)
value := sa.Value.Forward(ctx, hiddenState)
query = query.Reshape(ctx, headDim, opts.numHeads, query.Dim(1), batchSize)
key = key.Reshape(ctx, headDim, opts.numHeads, key.Dim(1), batchSize)
value = value.Reshape(ctx, headDim, opts.numHeads, value.Dim(1), batchSize)
attention := nn.Attention(ctx, query, key, value, 1.0/math.Sqrt(float64(headDim)), nil)
attention = attention.Reshape(ctx, opts.hiddenSize, attention.Dim(2), batchSize)
hiddenState = sa.Output.Forward(ctx, attention)
return hiddenState
}
type VisionMLP struct {
FC1 *nn.Linear `gguf:"fc1"`
FC2 *nn.Linear `gguf:"fc2"`
}
func (mlp *VisionMLP) Forward(ctx ml.Context, hiddenState ml.Tensor, opts *VisionModelOptions) ml.Tensor {
hiddenState = mlp.FC1.Forward(ctx, hiddenState).GELU(ctx)
hiddenState = mlp.FC2.Forward(ctx, hiddenState)
return hiddenState
}
type VisionEncoderLayer struct {
LayerNorm1 *nn.LayerNorm `gguf:"layer_norm1"`
SelfAttention *VisionSelfAttention
LayerNorm2 *nn.LayerNorm `gguf:"layer_norm2"`
MLP *VisionMLP `gguf:"mlp"`
}
func (e *VisionEncoderLayer) Forward(ctx ml.Context, hiddenState ml.Tensor, opts *VisionModelOptions) ml.Tensor {
residual := hiddenState
// self attention
hiddenState = e.LayerNorm1.Forward(ctx, hiddenState, opts.eps)
hiddenState = e.SelfAttention.Forward(ctx, hiddenState, opts)
hiddenState = hiddenState.Add(ctx, residual)
residual = hiddenState
// feed forward
hiddenState = e.LayerNorm2.Forward(ctx, hiddenState, opts.eps)
hiddenState = e.MLP.Forward(ctx, hiddenState, opts)
return hiddenState.Add(ctx, residual)
}
type VisionModelOptions struct {
hiddenSize, numHeads int
imageSize, patchSize int
eps float32
}
type VisionModel struct {
PatchEmbedding *nn.Conv2D `gguf:"patch_embedding"`
PositionEmbedding *nn.Embedding `gguf:"position_embedding"`
PostLayerNorm *nn.LayerNorm `gguf:"post_layernorm"`
Layers []VisionEncoderLayer `gguf:"blk"`
*VisionModelOptions
}
func (m *VisionModel) Forward(ctx ml.Context, pixelValues ml.Tensor) ml.Tensor {
numPatches := (m.imageSize / m.patchSize) * (m.imageSize / m.patchSize)
hiddenState := m.PatchEmbedding.Forward(ctx, pixelValues, m.patchSize, m.patchSize, 0, 0, 1, 1)
hiddenState = hiddenState.Reshape(ctx, numPatches, m.hiddenSize)
hiddenState = hiddenState.Permute(ctx, 1, 0, 2, 3).Contiguous(ctx)
positions := make([]int32, numPatches)
for i := range positions {
positions[i] = int32(i)
}
positionIDs, err := ctx.Input().FromIntSlice(positions, len(positions))
if err != nil {
panic(err)
}
hiddenState = hiddenState.Add(ctx, m.PositionEmbedding.Forward(ctx, positionIDs))
for _, layer := range m.Layers {
hiddenState = layer.Forward(ctx, hiddenState, m.VisionModelOptions)
}
hiddenState = m.PostLayerNorm.Forward(ctx, hiddenState, m.eps)
return hiddenState
}
func newVisionModel(c ml.Config) *VisionModel {
return &VisionModel{
Layers: make([]VisionEncoderLayer, c.Uint("vision.block_count")),
VisionModelOptions: &VisionModelOptions{
hiddenSize: int(c.Uint("vision.embedding_length")),
numHeads: int(c.Uint("vision.attention.head_count")),
imageSize: int(c.Uint("vision.image_size")),
patchSize: int(c.Uint("vision.patch_size")),
eps: c.Float("vision.attention.layer_norm_epsilon"),
},
}
}