File size: 25,310 Bytes
39d0c75
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
36fcf33
39d0c75
 
 
36fcf33
 
 
39d0c75
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
36fcf33
 
 
 
 
 
 
 
 
 
39d0c75
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
36fcf33
 
 
 
 
 
 
 
 
 
39d0c75
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
36fcf33
 
 
 
 
 
 
 
 
 
39d0c75
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
"""

Hugging Face Spaces deployment for SAM2 Auto Annotation API.

This file serves as the entry point for the FastAPI application on Hugging Face Spaces.

"""
import sys
import os

# Add sam2 folder to path to import from local sam2 directory
_current_dir = os.path.dirname(os.path.abspath(__file__))
_sam2_dir = os.path.join(_current_dir, "sam2")
# Add sam2 directory to sys.path if not already there
abs_sam2_dir = os.path.abspath(_sam2_dir)
if abs_sam2_dir not in sys.path:
    sys.path.insert(0, abs_sam2_dir)

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
import cv2
import numpy as np
import torch
import psutil
import PIL.Image
from requests.exceptions import Timeout, RequestException

# Import sam2 from local folder
from sam2.automatic_mask_generator import SAM2AutomaticMaskGenerator
from model.sam_model import predict_polygon, predict_polygon_from_point
from model.utils import load_image_from_url, mask_to_polygon
from model.sam2_detection_function import SAM2AutoAnnotation, create_sam2_auto_annotation

# Hugging Face model ID for SAM2.1 Hiera Large model
HUGGINGFACE_MODEL_ID = "facebook/sam2.1-hiera-large"
device = "cuda" if torch.cuda.is_available() else "cpu"

# Global SAM2 auto annotation (initialized once)
sam2_auto_annotation_global = None

app = FastAPI(
    title="SAM Auto Annotation API (BBox ➜ Polygon)",
    description="AI-powered auto-annotation API using Meta's Segment Anything Model (SAM)",
    version="1.0.0"
)

# Add CORS middleware to handle preflight OPTIONS requests
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Allows all origins
    allow_credentials=True,
    allow_methods=["*"],  # Allows all methods including OPTIONS
    allow_headers=["*"],  # Allows all headers
)


@app.get("/")
def root():
    """Root endpoint - API information."""
    return {
        "status": "Service is up and running!",
        "message": "Backend service is active",
        "api": "SAM Auto Annotation API",
        "version": "1.0.0"
    }


@app.get("/health")
def health_check():
    """Health check endpoint."""
    return {"status": "healthy", "service": "same model segmenticAPI"}


@app.post("/segment")
def segment(data: dict):
    """

    Segment image using SAM2 model to convert bounding box to polygon (CVAT-style).

    Bbox is used as a prompt to identify the object, not as a constraint.

    

    **Input:**

    ```json

    {

      "imageUrl": "https://example.com/image.jpg",

      "bbox": {"x": 494.97, "y": 187.22, "width": 137.99, "height": 98.00, "label": "Object"},

      "imageSize": {"width": 663.07, "height": 442}

    }

    ```

    

    OR

    

    ```json

    {

      "imageUrl": "https://example.com/image.jpg",

      "bbox": [494.97, 187.22, 137.99, 98.00],  // [x, y, width, height]

      "imageSize": [663.07, 442]  // [width, height]

    }

    ```

    

    **Output:**

    ```json

    {

      "polygon": [x1, y1, x2, y2, x3, y3, ...],  // CVAT format: flattened coordinates

      "confidence": 0.96

    }

    ```

    """
    try:
        # Validate input
        if "imageUrl" not in data:
            raise HTTPException(status_code=400, detail="Missing required field: imageUrl")
        if "bbox" not in data:
            raise HTTPException(status_code=400, detail="Missing required field: bbox")
        
        image_url = data["imageUrl"]
        bbox = data["bbox"]
        image_size = data.get("imageSize")  # Optional: for coordinate scaling
        
        # Validate bbox format
        if isinstance(bbox, dict):
            required_keys = ["x", "y", "width", "height"]
            if not all(key in bbox for key in required_keys):
                raise HTTPException(
                    status_code=400,
                    detail=f"bbox dict must contain: {required_keys}"
                )
        elif isinstance(bbox, list):
            if len(bbox) != 4:
                raise HTTPException(
                    status_code=400,
                    detail="bbox list must contain exactly 4 values: [x, y, width, height]"
                )
        else:
            raise HTTPException(
                status_code=400,
                detail="bbox must be either a dict or a list"
            )
        
        # Validate imageSize format if provided
        if image_size is not None:
            if isinstance(image_size, dict):
                if not ("width" in image_size and "height" in image_size):
                    raise HTTPException(
                        status_code=400,
                        detail="imageSize dict must contain 'width' and 'height'"
                    )
            elif isinstance(image_size, list):
                if len(image_size) != 2:
                    raise HTTPException(
                        status_code=400,
                        detail="imageSize list must contain exactly 2 values: [width, height]"
                    )
            else:
                raise HTTPException(
                    status_code=400,
                    detail="imageSize must be either a dict or a list"
                )
        
        # Load image from URL
        img_bgr = load_image_from_url(image_url)
        img_rgb = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2RGB)

        # Predict polygon using SAM2 (bbox as prompt, CVAT-style)
        mask, confidence, scale_factors = predict_polygon(img_rgb, bbox, image_size)
        
        # Convert mask to polygon (CVAT-style)
        polygon = mask_to_polygon(mask, scale_factors)
        
        if not polygon:
            raise HTTPException(status_code=400, detail="No polygon found in mask")

        return {
            "polygon": polygon,  # CVAT format: flattened coordinates
            "confidence": confidence
        }
    except KeyError as e:
        raise HTTPException(status_code=400, detail=f"Missing required field: {str(e)}")
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except FileNotFoundError as e:
        raise HTTPException(status_code=500, detail=str(e))
    except ImportError as e:
        raise HTTPException(
            status_code=500,
            detail=f"Segment Anything library not installed. Please run: pip install -e . in segment-anything directory"
        )
    except Timeout as e:
        raise HTTPException(
            status_code=504,
            detail=f"Image download timeout: {str(e)}. The image server may be slow or unreachable. Please try again or use a different image URL."
        )
    except RequestException as e:
        raise HTTPException(
            status_code=502,
            detail=f"Failed to fetch image from URL: {str(e)}. Please check the image URL and try again."
        )
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal server error: {str(e)}")


@app.post("/segment/point")
def segment_from_point(data: dict):
    """

    Segment image using SAM2 model with a point click to select object.

    The point identifies which object to segment.

    

    **Input:**

    ```json

    {

      "imageUrl": "https://example.com/image.jpg",

      "point": {"x": 494.97, "y": 187.22},

      "imageSize": {"width": 663.07, "height": 442}

    }

    ```

    

    OR

    

    ```json

    {

      "imageUrl": "https://example.com/image.jpg",

      "point": [494.97, 187.22],  // [x, y]

      "imageSize": [663.07, 442]  // [width, height]

    }

    ```

    

    **Output:**

    ```json

    {

      "polygon": [x1, y1, x2, y2, x3, y3, ...],  // CVAT format: flattened coordinates

      "confidence": 0.96

    }

    ```

    """
    try:
        # Validate input
        if "imageUrl" not in data:
            raise HTTPException(status_code=400, detail="Missing required field: imageUrl")
        if "point" not in data:
            raise HTTPException(status_code=400, detail="Missing required field: point")
        
        image_url = data["imageUrl"]
        point = data["point"]
        image_size = data.get("imageSize")  # Optional: for coordinate scaling
        
        # Validate point format
        if isinstance(point, dict):
            required_keys = ["x", "y"]
            if not all(key in point for key in required_keys):
                raise HTTPException(
                    status_code=400,
                    detail=f"point dict must contain: {required_keys}"
                )
        elif isinstance(point, list):
            if len(point) != 2:
                raise HTTPException(
                    status_code=400,
                    detail="point list must contain exactly 2 values: [x, y]"
                )
        else:
            raise HTTPException(
                status_code=400,
                detail="point must be either a dict or a list"
            )
        
        # Validate imageSize format if provided
        if image_size is not None:
            if isinstance(image_size, dict):
                if not ("width" in image_size and "height" in image_size):
                    raise HTTPException(
                        status_code=400,
                        detail="imageSize dict must contain 'width' and 'height'"
                    )
            elif isinstance(image_size, list):
                if len(image_size) != 2:
                    raise HTTPException(
                        status_code=400,
                        detail="imageSize list must contain exactly 2 values: [width, height]"
                    )
            else:
                raise HTTPException(
                    status_code=400,
                    detail="imageSize must be either a dict or a list"
                )
        
        # Load image from URL
        img_bgr = load_image_from_url(image_url)
        img_rgb = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2RGB)

        # Predict polygon using SAM2 (point click as prompt)
        mask, confidence, scale_factors = predict_polygon_from_point(img_rgb, point, image_size)
        
        # Convert mask to polygon (CVAT-style)
        polygon = mask_to_polygon(mask, scale_factors)
        
        if not polygon:
            raise HTTPException(status_code=400, detail="No polygon found in mask. Try clicking on a different point.")

        return {
            "polygon": polygon,  # CVAT format: flattened coordinates
            "confidence": confidence
        }
    except KeyError as e:
        raise HTTPException(status_code=400, detail=f"Missing required field: {str(e)}")
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except FileNotFoundError as e:
        raise HTTPException(status_code=500, detail=str(e))
    except ImportError as e:
        raise HTTPException(
            status_code=500,
            detail=f"Segment Anything library not installed. Please run: pip install -e . in segment-anything directory"
        )
    except Timeout as e:
        raise HTTPException(
            status_code=504,
            detail=f"Image download timeout: {str(e)}. The image server may be slow or unreachable. Please try again or use a different image URL."
        )
    except RequestException as e:
        raise HTTPException(
            status_code=502,
            detail=f"Failed to fetch image from URL: {str(e)}. Please check the image URL and try again."
        )
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal server error: {str(e)}")


@app.post("/auto-annotate")
def auto_annotate(data: dict):
    """

    Automatically detect and segment all objects in an image using SAM2 from Hugging Face.

    Uses SAM2AutomaticMaskGenerator (facebook/sam2.1-hiera-large) to detect all objects without requiring prompts (bbox or points).

    

    **Input:**

    ```json

    {

      "imageUrl": "https://example.com/image.jpg",

      "imageSize": {"width": 663.07, "height": 442},

      "minArea": 100,

      "minConfidence": 0.5,

      "maxImageDimension": 1024,

      "pointsPerSide": 32,

      "pointsPerBatch": 64,

      "filterObjectsOnly": true

    }

    ```

    

    **Output:**

    ```json

    {

      "masks": [

        {

          "polygon": [x1, y1, x2, y2, x3, y3, ...],

          "confidence": 0.93,

          "area": 12345

        },

        ...

      ],

      "count": 10,

      "memoryInfo": {

        "before_mb": 512.5,

        "after_mb": 1024.3,

        "peak_mb": 1024.3,

        "estimated_mb": 800.0,

        "memory_used_mb": 511.8

      },

      "imageInfo": {

        "wasResized": true,

        "originalSize": [1920, 1080],

        "processedSize": [1024, 576],

        "resizeScale": [1.875, 1.875]

      }

    }

    ```

    """
    try:
        # Validate input
        if "imageUrl" not in data:
            raise HTTPException(status_code=400, detail="Missing required field: imageUrl")
        
        image_url = data["imageUrl"]
        image_size = data.get("imageSize")  # Optional: for coordinate scaling
        min_area = data.get("minArea", 100)  # Optional: minimum mask area
        min_confidence = data.get("minConfidence", 0.5)  # Optional: minimum confidence
        max_image_dimension = data.get("maxImageDimension", 1024)  # Optional: max dimension before resizing
        # Lower default values for faster processing
        points_per_side = data.get("pointsPerSide", 32)  # Optional: points per side (lower = faster)
        points_per_batch = data.get("pointsPerBatch", 64)  # Optional: points per batch (lower = faster)
        filter_objects_only = data.get("filterObjectsOnly", False)  # Optional: filter out background masks
        
        # Validate imageSize format if provided
        if image_size is not None:
            if isinstance(image_size, dict):
                if not ("width" in image_size and "height" in image_size):
                    raise HTTPException(
                        status_code=400,
                        detail="imageSize dict must contain 'width' and 'height'"
                    )
            elif isinstance(image_size, list):
                if len(image_size) != 2:
                    raise HTTPException(
                        status_code=400,
                        detail="imageSize list must contain exactly 2 values: [width, height]"
                    )
            else:
                raise HTTPException(
                    status_code=400,
                    detail="imageSize must be either a dict or a list"
                )
        
        # Validate minArea and minConfidence
        try:
            min_area = int(min_area)
            if min_area < 0:
                raise HTTPException(status_code=400, detail="minArea must be >= 0")
        except (ValueError, TypeError):
            raise HTTPException(status_code=400, detail="minArea must be an integer")
        
        try:
            min_confidence = float(min_confidence)
            if not (0.0 <= min_confidence <= 1.0):
                raise HTTPException(status_code=400, detail="minConfidence must be between 0.0 and 1.0")
        except (ValueError, TypeError):
            raise HTTPException(status_code=400, detail="minConfidence must be a float between 0.0 and 1.0")
        
        # Validate maxImageDimension
        try:
            max_image_dimension = int(max_image_dimension)
            if max_image_dimension < 256:
                raise HTTPException(status_code=400, detail="maxImageDimension must be >= 256")
            if max_image_dimension > 4096:
                raise HTTPException(status_code=400, detail="maxImageDimension must be <= 4096")
        except (ValueError, TypeError):
            raise HTTPException(status_code=400, detail="maxImageDimension must be an integer between 256 and 4096")
        
        # Validate pointsPerSide
        try:
            points_per_side = int(points_per_side)
            if points_per_side < 8:
                raise HTTPException(status_code=400, detail="pointsPerSide must be >= 8")
            if points_per_side > 128:
                raise HTTPException(status_code=400, detail="pointsPerSide must be <= 128")
        except (ValueError, TypeError):
            raise HTTPException(status_code=400, detail="pointsPerSide must be an integer between 8 and 128")
        
        # Validate pointsPerBatch
        try:
            points_per_batch = int(points_per_batch)
            if points_per_batch < 16:
                raise HTTPException(status_code=400, detail="pointsPerBatch must be >= 16")
            if points_per_batch > 256:
                raise HTTPException(status_code=400, detail="pointsPerBatch must be <= 256")
        except (ValueError, TypeError):
            raise HTTPException(status_code=400, detail="pointsPerBatch must be an integer between 16 and 256")
        
        # Get memory before processing
        process = psutil.Process(os.getpid())
        memory_before = process.memory_info().rss / (1024 * 1024)  # MB
        
        # Load image from URL
        img_bgr = load_image_from_url(image_url)
        img_rgb = cv2.cvtColor(img_bgr, cv2.COLOR_BGR2RGB)
        
        # Resize image if needed to reduce memory usage
        original_h, original_w = img_rgb.shape[:2]
        original_size = [original_w, original_h]
        
        processed_image = img_rgb
        resize_scale = [1.0, 1.0]
        was_resized = False
        
        if max(original_h, original_w) > max_image_dimension:
            was_resized = True
            if original_h > original_w:
                new_h = max_image_dimension
                new_w = int(original_w * (max_image_dimension / original_h))
            else:
                new_w = max_image_dimension
                new_h = int(original_h * (max_image_dimension / original_w))
            processed_image = cv2.resize(img_rgb, (new_w, new_h), interpolation=cv2.INTER_LINEAR)
            resize_scale = [original_w / new_w, original_h / new_h]
        
        processed_h, processed_w = processed_image.shape[:2]
        processed_size = [processed_w, processed_h]
        
        # Estimate memory requirements
        estimated_mb = ((processed_w * processed_h * 3 * 4) + (processed_w * processed_h * 256 * 4) + (processed_w * processed_h * 100 * 1)) / (1024 * 1024)
        
        # Calculate scale factors for coordinate scaling (matching predict_polygon_from_point logic)
        # We need to scale FROM processed image TO display size (imageSize)
        # mask_to_polygon expects scale_factors that represent: FROM processed TO display
        # It divides by these factors, so we pass (processed_w/display_w, processed_h/display_h)
        scale_factor_x, scale_factor_y = 1.0, 1.0
        
        if image_size is not None:
            if isinstance(image_size, dict):
                display_w = float(image_size.get("width", processed_w))
                display_h = float(image_size.get("height", processed_h))
            else:
                display_w, display_h = float(image_size[0]), float(image_size[1])
            
            # Calculate scale factors: FROM processed image TO display size
            # These will be used in mask_to_polygon: polygon / scale_factor = display coords
            scale_factor_x = processed_w / display_w if display_w > 0 else 1.0
            scale_factor_y = processed_h / display_h if display_h > 0 else 1.0
        
        # Get image dimensions for filtering
        total_image_area = processed_w * processed_h
        
        # Initialize SAM2 Auto Annotation
        # This uses facebook/sam2.1-hiera-large model from Hugging Face
        # Cache the annotation instance globally to avoid reloading on every request
        global sam2_auto_annotation_global
        
        if sam2_auto_annotation_global is None:
            try:
                sam2_auto_annotation_global = create_sam2_auto_annotation(
                    points_per_side=points_per_side,
                    points_per_batch=points_per_batch,
                    pred_iou_thresh=0.88,
                    stability_score_thresh=0.95,
                    min_mask_region_area=min_area,
                )
            except ImportError as e:
                raise HTTPException(
                    status_code=500,
                    detail=f"Failed to import required modules. Please ensure 'sam2' and 'huggingface_hub' are installed. Error: {str(e)}"
                )
            except Exception as e:
                raise HTTPException(
                    status_code=500,
                    detail=f"Failed to load SAM2 Auto Annotation from Hugging Face ({HUGGINGFACE_MODEL_ID}). Error: {str(e)}"
                )
        
        # Generate masks using SAM2AutoAnnotation with proper scaling (matching predict_polygon_from_point)
        # Pass scale_factors to scale FROM processed image TO display size
        mask_results = sam2_auto_annotation_global.generate_masks(
            image=processed_image,
            min_confidence=min_confidence,
            min_area=min_area,
            filter_blank_regions=True,
            scale_factors=(scale_factor_x, scale_factor_y)
        )
        
        # Get memory after processing
        memory_after = process.memory_info().rss / (1024 * 1024)  # MB
        memory_used = memory_after - memory_before
        
        # Process mask results (polygons are already scaled to display size by generate_masks)
        results = []
        
        for mask_result in mask_results:
            # Extract mask information
            polygon = mask_result.get("polygon")
            score = mask_result.get("confidence")
            area = mask_result.get("area")
            
            # Early filtering: Skip masks that don't meet basic criteria
            if area < min_area or score < min_confidence:
                continue
            
            # Filter out background masks if filterObjectsOnly is True
            if filter_objects_only:
                coverage_ratio = area / total_image_area if total_image_area > 0 else 0
                if coverage_ratio >= 0.8:  # Skip masks covering >80% (likely background)
                    continue
            
            # Polygon is already scaled to display size by generate_masks (using mask_to_polygon with scale_factors)
            # Return polygon in flattened format [x1, y1, x2, y2, ...]
            if polygon and len(polygon) >= 6:  # At least 3 points
                mask_obj = {
                    "polygon": polygon  # Already in flattened format and scaled to display size
                }
                if score is not None:
                    mask_obj["confidence"] = score
                if area is not None:
                    mask_obj["area"] = area
                results.append(mask_obj)
        
        # Build response with all required fields
        response = {
            "masks": results,
            "count": len(results),
            "memoryInfo": {
                "before_mb": round(memory_before, 2),
                "after_mb": round(memory_after, 2),
                "peak_mb": round(memory_after, 2),
                "estimated_mb": round(estimated_mb, 2),
                "memory_used_mb": round(memory_used, 2)
            },
            "imageInfo": {
                "wasResized": was_resized,
                "originalSize": original_size,
                "processedSize": processed_size,
                "resizeScale": resize_scale
            }
        }
        
        return response
        
    except KeyError as e:
        raise HTTPException(status_code=400, detail=f"Missing required field: {str(e)}")
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except FileNotFoundError as e:
        raise HTTPException(status_code=500, detail=str(e))
    except ImportError as e:
        raise HTTPException(
            status_code=500,
            detail=f"Segment Anything library not installed. Please ensure 'sam2' and 'huggingface_hub' are installed."
        )
    except Timeout as e:
        raise HTTPException(
            status_code=504,
            detail=f"Image download timeout: {str(e)}. The image server may be slow or unreachable. Please try again or use a different image URL."
        )
    except RequestException as e:
        raise HTTPException(
            status_code=502,
            detail=f"Failed to fetch image from URL: {str(e)}. Please check the image URL and try again."
        )
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal server error: {str(e)}")