reduce kernel size, add TODO for loading from config

model/models/gemma3/model.go

@@ -90,7 +90,11 @@ func (m *Model) EncodeMultimodal(ctx ml.Context, multimodalData []byte) (any, er
 	visionOutputs := m.VisionModel.Forward(ctx, pixelValues)
 	visionOutputs = visionOutputs.Permute(ctx, 1, 0, 2, 3).Contiguous(ctx)
 	patchesPerImage := m.ImageProcessor.imageSize / m.ImageProcessor.patchSize
-	kernelSize := patchesPerImage * patchesPerImage / 256
+
+	// TODO (jmorganca): read this from the model config
+	// it should instead be math.Sqrt(tokens per image)
+	tokensPerSide := 8
+	kernelSize := patchesPerImage / tokensPerSide
 	visionOutputs = visionOutputs.AvgPool1D(ctx, kernelSize, kernelSize, 0)
 
 	visionOutputs = visionOutputs.Permute(ctx, 1, 0, 2, 3).Contiguous(ctx)