Add bbox coordinates and colorbar for geo-aligned overlay

app.py

@@ -150,6 +150,10 @@ class HeatmapResponse(BaseModel):
     timestamp: str
     image_date: Optional[str] = None
     image_size: Optional[str] = None
+    # Bounding box for geo-alignment [sw_lon, sw_lat, ne_lon, ne_lat]
+    bbox: Optional[List[float]] = None
+    # Separate colorbar image (horizontal) for UI display
+    colorbar_base64: Optional[str] = None
     # Patch analysis (for pixel-wise)
     num_patches: Optional[int] = None
     health_summary: Optional[dict] = None
@@ -175,6 +179,37 @@ def get_stress_colormap():
     colors = [(0.2, 0.7, 0.2), (0.8, 0.8, 0.2), (0.9, 0.5, 0.1), (0.8, 0.2, 0.2)]
     return LinearSegmentedColormap.from_list('stress', colors, N=256)
 
+def generate_colorbar_image(min_val: float, max_val: float, index_type: str, is_stress: bool = False) -> str:
+    """Generate a separate horizontal colorbar image for UI display."""
+    if is_stress:
+        cmap = get_stress_colormap()
+        label = 'Stress Level'
+    elif index_type in ['NDWI', 'SMI']:
+        cmap = get_water_colormap()
+        label = index_type
+    else:
+        cmap = get_vegetation_colormap()
+        label = index_type
+    
+    fig, ax = plt.subplots(figsize=(6, 0.5), dpi=100)
+    
+    # Create gradient
+    gradient = np.linspace(0, 1, 256).reshape(1, -1)
+    ax.imshow(gradient, aspect='auto', cmap=cmap)
+    
+    # Labels
+    ax.set_xticks([0, 127, 255])
+    ax.set_xticklabels([f'{min_val:.2f}', f'{(min_val+max_val)/2:.2f}', f'{max_val:.2f}'], fontsize=8)
+    ax.set_yticks([])
+    ax.set_xlabel(label, fontsize=9)
+    
+    buf = io.BytesIO()
+    plt.savefig(buf, format='png', bbox_inches='tight', pad_inches=0.1, facecolor='white')
+    plt.close(fig)
+    buf.seek(0)
+    
+    return base64.b64encode(buf.getvalue()).decode('utf-8')
+
 # ============================================================================
 # EVALSCRIPT
 # ============================================================================
@@ -423,6 +458,14 @@ async def generate_heatmap(request: HeatmapRequest):
             request.center_lon + lon_off, request.center_lat + lat_off
         ), crs=CRS.WGS84)
         
+        # Store bbox coordinates for response [sw_lon, sw_lat, ne_lon, ne_lat]
+        bbox_coords = [
+            request.center_lon - lon_off,  # SW lon
+            request.center_lat - lat_off,  # SW lat
+            request.center_lon + lon_off,  # NE lon
+            request.center_lat + lat_off   # NE lat
+        ]
+        
         size = bbox_to_dimensions(bbox, resolution=10)
         log_detail("Image Size", f"{size[0]}×{size[1]} pixels")
         
@@ -476,6 +519,11 @@ async def generate_heatmap(request: HeatmapRequest):
             
             log_section(f"SUCCESS [{req_id}]")
             
+            # Generate colorbar if in overlay mode
+            colorbar_b64 = None
+            if request.overlay_mode:
+                colorbar_b64 = generate_colorbar_image(min_v, max_v, index_type, is_stress=False)
+            
             return HeatmapResponse(
                 success=True,
                 metric=request.metric,
@@ -488,6 +536,8 @@ async def generate_heatmap(request: HeatmapRequest):
                 timestamp=datetime.now().isoformat(),
                 image_date=end_date.strftime('%Y-%m-%d'),
                 image_size=f"{size[0]}x{size[1]}",
+                bbox=bbox_coords,
+                colorbar_base64=colorbar_b64,
                 num_patches=len(patches_list),
                 health_summary=health_summary
             )
@@ -557,6 +607,11 @@ async def generate_heatmap(request: HeatmapRequest):
             
             log_section(f"SUCCESS [{req_id}]")
             
+            # Generate colorbar if in overlay mode
+            colorbar_b64 = None
+            if request.overlay_mode:
+                colorbar_b64 = generate_colorbar_image(min_v, max_v, "Stress", is_stress=True)
+            
             return HeatmapResponse(
                 success=True,
                 metric=request.metric,
@@ -569,6 +624,8 @@ async def generate_heatmap(request: HeatmapRequest):
                 timestamp=datetime.now().isoformat(),
                 image_date=end_date.strftime('%Y-%m-%d'),
                 image_size=f"{size[0]}x{size[1]}",
+                bbox=bbox_coords,
+                colorbar_base64=colorbar_b64,
                 level=llm_result.get('level', 'Unknown'),
                 analysis=llm_result.get('analysis', ''),
                 stress_score=float(stress_results['stress_scores'].mean()),