blip2_image_text_matching.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import torch\n",
    "from PIL import Image\n",
    "\n",
    "from lavis.models import load_model_and_preprocess\n",
    "from lavis.processors import load_processor"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Load an example image and text"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "raw_image = Image.open(\"../docs/_static/merlion.png\").convert(\"RGB\")\n",
    "display(raw_image.resize((596, 437)))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# setup device to use\n",
    "device = torch.device(\"cuda\") if torch.cuda.is_available() else \"cpu\""
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "caption = \"merlion in Singapore\""
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Load model and preprocessors"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "model, vis_processors, text_processors = load_model_and_preprocess(\"blip2_image_text_matching\", \"pretrain\", device=device, is_eval=True)\n",
    "# model, vis_processors, text_processors = load_model_and_preprocess(\"blip2_image_text_matching\", \"coco\", device=device, is_eval=True)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Preprocess image and text inputs"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "img = vis_processors[\"eval\"](raw_image).unsqueeze(0).to(device)\n",
    "txt = text_processors[\"eval\"](caption)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Compute image-text matching (ITM) score"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "itm_output = model({\"image\": img, \"text_input\": txt}, match_head=\"itm\")\n",
    "itm_scores = torch.nn.functional.softmax(itm_output, dim=1)\n",
    "print(f'The image and text are matched with a probability of {itm_scores[:, 1].item():.3%}')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "itc_score = model({\"image\": img, \"text_input\": txt}, match_head='itc')\n",
    "print('The image feature and text feature has a cosine similarity of %.4f'%itc_score)"
   ]
  }
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