Paligemma siglip vision config (#2518)

* Add the paligemma siglip vision config.

* More paligemma configs.

candle-transformers/src/models/siglip.rs

@@ -83,6 +83,60 @@ impl TransformerConfig for VisionConfig {
     }
 }
 
+impl VisionConfig {
+    pub fn paligemma_3b_224() -> Self {
+        Self {
+            // https://huggingface.co/google/paligemma-3b-pt-224/blob/main/config.json
+            patch_size: 14,
+            num_attention_heads: 16,
+            num_hidden_layers: 27,
+            hidden_size: 1152,
+            intermediate_size: 4304,
+            image_size: 224, // num_image_tokens: (224 / 14)^2 = 256
+            // Default values.
+            num_channels: 3,
+            hidden_act: candle_nn::Activation::GeluPytorchTanh,
+            layer_norm_eps: 1e-6,
+        }
+    }
+
+    pub fn paligemma_3b_448() -> Self {
+        Self {
+            // https://huggingface.co/google/paligemma-3b-pt-448/blob/main/config.json
+            patch_size: 14,
+            num_attention_heads: 16,
+            num_hidden_layers: 27,
+            hidden_size: 1152,
+            intermediate_size: 4304,
+            image_size: 448, // num_image_tokens: (448 / 14)^2 = 1024
+            // Default values.
+            num_channels: 3,
+            hidden_act: candle_nn::Activation::GeluPytorchTanh,
+            layer_norm_eps: 1e-6,
+        }
+    }
+
+    pub fn paligemma_3b_896() -> Self {
+        Self {
+            // https://huggingface.co/google/paligemma-3b-pt-448/blob/main/config.json
+            patch_size: 14,
+            num_attention_heads: 16,
+            num_hidden_layers: 27,
+            hidden_size: 1152,
+            intermediate_size: 4304,
+            image_size: 896, // num_image_tokens: (896 / 14)^2 = 4096
+            // Default values.
+            num_channels: 3,
+            hidden_act: candle_nn::Activation::GeluPytorchTanh,
+            layer_norm_eps: 1e-6,
+        }
+    }
+
+    pub fn num_patches(&self) -> usize {
+        (self.image_size / self.patch_size).pow(2)
+    }
+}
+
 // https://github.com/huggingface/transformers/blob/2e24ee4dfa39cc0bc264b89edbccc373c8337086/src/transformers/models/siglip/configuration_siglip.py#L228
 #[derive(serde::Deserialize, Clone, Debug)]
 pub struct Config {