XAI optimizatoin

dashboard.py

@@ -127,7 +127,7 @@ _unnorm = transforms.Normalize(
     mean=[-0.485 / 0.229, -0.456 / 0.224, -0.406 / 0.225],
     std=[1 / 0.229, 1 / 0.224, 1 / 0.225],
 )
-score_cam = ScoreCAM(model=model, target_layers=[model.features[7][0]])
+score_cam = ScoreCAM(model=model, target_layers=[model.features[-1]])
 lime_exp = lime_image.LimeImageExplainer(random_state=SEED)
 
 
@@ -170,23 +170,6 @@ def _save_img(arr, path):
     Image.fromarray(arr).save(path)
 
 
-def _prob_chart(probs, pred_idx, path):
-    fig, ax = plt.subplots(figsize=(5, 2.6))
-    colors = ["#e8832a" if i == pred_idx else "#4a90d9" for i in range(len(CLASS_NAMES))]
-    bars = ax.barh(CLASS_NAMES, probs, color=colors)
-    ax.set_xlim(0, 1)
-    ax.set_xlabel("Probability")
-    for bar, p in zip(bars, probs):
-        if p > 0.05:
-            ax.text(bar.get_width() - 0.01,
-                    bar.get_y() + bar.get_height() / 2,
-                    f"{p:.2f}", va="center", ha="right",
-                    fontsize=8, color="white", fontweight="bold")
-    plt.tight_layout()
-    fig.savefig(path, dpi=120, bbox_inches="tight")
-    plt.close(fig)
-
-
 def compute_xai(det):
     out = XAI_DIR / det["id"]
     if (out / "meta.json").exists():
@@ -204,19 +187,27 @@ def compute_xai(det):
 
     _save_img(raw, out / "original.png")
 
+    # single forward pass: probabilities + feature vector for neighbours
     with torch.no_grad():
-        probs = torch.nn.functional.softmax(model(inp), dim=1).cpu().squeeze()
+        feats = model.features(inp)
+        pooled = model.avgpool(feats)
+        logits = model.classifier(torch.flatten(pooled, 1))
+        probs = torch.nn.functional.softmax(logits, dim=1).cpu().squeeze()
+        qf = torch.nn.functional.normalize(
+            torch.flatten(pooled, 1).cpu(), dim=1,
+        ).squeeze()
     pred_idx = probs.argmax().item()
     entropy = -(probs * torch.log(probs + 1e-12)).sum().item()
-    _prob_chart(probs.numpy(), pred_idx, out / "chart.png")
 
+    # ScoreCAM
     hm = score_cam(input_tensor=inp, targets=None)
     _save_img(
         show_cam_on_image(raw.astype(np.float32), hm.squeeze(), use_rgb=True, image_weight=0.75),
         out / "scorecam.png",
     )
 
-    expl = lime_exp.explain_instance(raw, _lime_predict, top_labels=2, hide_color=0, num_samples=1000)
+    # LIME (reduced from 1000 to 500 samples)
+    expl = lime_exp.explain_instance(raw, _lime_predict, top_labels=2, hide_color=0, num_samples=500)
     c1, c2 = expl.top_labels[0], expl.top_labels[1]
     t1, m1 = expl.get_image_and_mask(c1, positive_only=False, num_features=10, hide_rest=False)
     t2, m2 = expl.get_image_and_mask(c2, positive_only=False, num_features=10, hide_rest=False)
@@ -233,10 +224,7 @@ def compute_xai(det):
     col = plt.cm.RdBu_r((diff + 1) / 2)[:, :, :3]
     _save_img((0.6 * raw + 0.4 * col).clip(0, 1), out / "contrastive.png")
 
-    with torch.no_grad():
+    # nearest neighbours (reuse qf from above)
-        qf = torch.nn.functional.normalize(
-            torch.flatten(model.avgpool(model.features(inp)), 1).cpu(), dim=1,
-        ).squeeze()
     sims, idxs = (train_feats @ qf).topk(3)
     nbs = []
     for k, (ni, ns) in enumerate(zip(idxs, sims)):
@@ -337,7 +325,7 @@ def api_xai(det_id):
     base = f"/xai/{det_id}"
     meta["urls"] = {
         k: f"{base}/{k}.png"
-        for k in ["original", "chart", "scorecam", "lime1", "lime2", "contrastive",
+        for k in ["original", "scorecam", "lime1", "lime2", "contrastive",
                    "nb1", "nb2", "nb3"]
     }
     return jsonify(meta)