Add model card

This PR adds a model card, with installation and usage sections, and links to https://huggingface.co/papers/2403.15378.

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README.md

@@ -1,3 +1,45 @@
----
-license: apache-2.0
----
+---
+license: apache-2.0
+pipeline_tag: zero-shot-image-classification
+library_name: openclip
+---
+
+# LongCLIP model
+
+This repository contains the weights of the LongCLIP model.
+
+Paper: https://huggingface.co/papers/2403.15378
+
+Github repository: https://github.com/beichenzbc/long-clip
+
+## Installation
+
+```bash
+git clone https://github.com/beichenzbc/Long-CLIP.git
+cd Long-CLIP
+```
+
+## Usage
+
+```
+from model import longclip
+import torch
+from PIL import Image
+from huggingface_hub import hf_hub_download
+
+device = "cuda" if torch.cuda.is_available() else "cpu"
+filepath = hf_hub_download(repo_id="BeichenZhang/LongCLIP-L-336px", filename="longclip-L@336px.pt")
+model, preprocess = longclip.load(filepath, device=device)
+
+text = longclip.tokenize(["A man is crossing the street with a red car parked nearby.", "A man is driving a car in an urban scene."]).to(device)
+image = preprocess(Image.open("./img/demo.png")).unsqueeze(0).to(device)
+
+with torch.no_grad():
+    image_features = model.encode_image(image)
+    text_features = model.encode_text(text)
+    
+    logits_per_image = image_features @ text_features.T
+    probs = logits_per_image.softmax(dim=-1).cpu().numpy()
+
+print("Label probs:", probs)
+```