Spaces:
Sleeping
Sleeping
import warnings | |
import cv2 | |
import numpy as np | |
import torch | |
from kornia.color import rgb_to_grayscale | |
from omegaconf import OmegaConf | |
from packaging import version | |
try: | |
import pycolmap | |
except ImportError: | |
pycolmap = None | |
from hloc import logger | |
from ..utils.base_model import BaseModel | |
def filter_dog_point( | |
points, scales, angles, image_shape, nms_radius, scores=None | |
): | |
h, w = image_shape | |
ij = np.round(points - 0.5).astype(int).T[::-1] | |
# Remove duplicate points (identical coordinates). | |
# Pick highest scale or score | |
s = scales if scores is None else scores | |
buffer = np.zeros((h, w)) | |
np.maximum.at(buffer, tuple(ij), s) | |
keep = np.where(buffer[tuple(ij)] == s)[0] | |
# Pick lowest angle (arbitrary). | |
ij = ij[:, keep] | |
buffer[:] = np.inf | |
o_abs = np.abs(angles[keep]) | |
np.minimum.at(buffer, tuple(ij), o_abs) | |
mask = buffer[tuple(ij)] == o_abs | |
ij = ij[:, mask] | |
keep = keep[mask] | |
if nms_radius > 0: | |
# Apply NMS on the remaining points | |
buffer[:] = 0 | |
buffer[tuple(ij)] = s[keep] # scores or scale | |
local_max = torch.nn.functional.max_pool2d( | |
torch.from_numpy(buffer).unsqueeze(0), | |
kernel_size=nms_radius * 2 + 1, | |
stride=1, | |
padding=nms_radius, | |
).squeeze(0) | |
is_local_max = buffer == local_max.numpy() | |
keep = keep[is_local_max[tuple(ij)]] | |
return keep | |
def sift_to_rootsift(x: torch.Tensor, eps=1e-6) -> torch.Tensor: | |
x = torch.nn.functional.normalize(x, p=1, dim=-1, eps=eps) | |
x.clip_(min=eps).sqrt_() | |
return torch.nn.functional.normalize(x, p=2, dim=-1, eps=eps) | |
def run_opencv_sift(features: cv2.Feature2D, image: np.ndarray) -> np.ndarray: | |
""" | |
Detect keypoints using OpenCV Detector. | |
Optionally, perform description. | |
Args: | |
features: OpenCV based keypoints detector and descriptor | |
image: Grayscale image of uint8 data type | |
Returns: | |
keypoints: 1D array of detected cv2.KeyPoint | |
scores: 1D array of responses | |
descriptors: 1D array of descriptors | |
""" | |
detections, descriptors = features.detectAndCompute(image, None) | |
points = np.array([k.pt for k in detections], dtype=np.float32) | |
scores = np.array([k.response for k in detections], dtype=np.float32) | |
scales = np.array([k.size for k in detections], dtype=np.float32) | |
angles = np.deg2rad( | |
np.array([k.angle for k in detections], dtype=np.float32) | |
) | |
return points, scores, scales, angles, descriptors | |
class SIFT(BaseModel): | |
default_conf = { | |
"rootsift": True, | |
"nms_radius": 0, # None to disable filtering entirely. | |
"max_keypoints": 4096, | |
"backend": "opencv", # in {opencv, pycolmap, pycolmap_cpu, pycolmap_cuda} | |
"detection_threshold": 0.0066667, # from COLMAP | |
"edge_threshold": 10, | |
"first_octave": -1, # only used by pycolmap, the default of COLMAP | |
"num_octaves": 4, | |
} | |
required_data_keys = ["image"] | |
def _init(self, conf): | |
self.conf = OmegaConf.create(self.conf) | |
backend = self.conf.backend | |
if backend.startswith("pycolmap"): | |
if pycolmap is None: | |
raise ImportError( | |
"Cannot find module pycolmap: install it with pip" | |
"or use backend=opencv." | |
) | |
options = { | |
"peak_threshold": self.conf.detection_threshold, | |
"edge_threshold": self.conf.edge_threshold, | |
"first_octave": self.conf.first_octave, | |
"num_octaves": self.conf.num_octaves, | |
"normalization": pycolmap.Normalization.L2, # L1_ROOT is buggy. | |
} | |
device = ( | |
"auto" | |
if backend == "pycolmap" | |
else backend.replace("pycolmap_", "") | |
) | |
if ( | |
backend == "pycolmap_cpu" or not pycolmap.has_cuda | |
) and pycolmap.__version__ < "0.5.0": | |
warnings.warn( | |
"The pycolmap CPU SIFT is buggy in version < 0.5.0, " | |
"consider upgrading pycolmap or use the CUDA version.", | |
stacklevel=1, | |
) | |
else: | |
options["max_num_features"] = self.conf.max_keypoints | |
self.sift = pycolmap.Sift(options=options, device=device) | |
elif backend == "opencv": | |
self.sift = cv2.SIFT_create( | |
contrastThreshold=self.conf.detection_threshold, | |
nfeatures=self.conf.max_keypoints, | |
edgeThreshold=self.conf.edge_threshold, | |
nOctaveLayers=self.conf.num_octaves, | |
) | |
else: | |
backends = {"opencv", "pycolmap", "pycolmap_cpu", "pycolmap_cuda"} | |
raise ValueError( | |
f"Unknown backend: {backend} not in " | |
f"{{{','.join(backends)}}}." | |
) | |
logger.info("Load SIFT model done.") | |
def extract_single_image(self, image: torch.Tensor): | |
image_np = image.cpu().numpy().squeeze(0) | |
if self.conf.backend.startswith("pycolmap"): | |
if version.parse(pycolmap.__version__) >= version.parse("0.5.0"): | |
detections, descriptors = self.sift.extract(image_np) | |
scores = None # Scores are not exposed by COLMAP anymore. | |
else: | |
detections, scores, descriptors = self.sift.extract(image_np) | |
keypoints = detections[:, :2] # Keep only (x, y). | |
scales, angles = detections[:, -2:].T | |
if scores is not None and ( | |
self.conf.backend == "pycolmap_cpu" or not pycolmap.has_cuda | |
): | |
# Set the scores as a combination of abs. response and scale. | |
scores = np.abs(scores) * scales | |
elif self.conf.backend == "opencv": | |
# TODO: Check if opencv keypoints are already in corner convention | |
keypoints, scores, scales, angles, descriptors = run_opencv_sift( | |
self.sift, (image_np * 255.0).astype(np.uint8) | |
) | |
pred = { | |
"keypoints": keypoints, | |
"scales": scales, | |
"oris": angles, | |
"descriptors": descriptors, | |
} | |
if scores is not None: | |
pred["scores"] = scores | |
# sometimes pycolmap returns points outside the image. We remove them | |
if self.conf.backend.startswith("pycolmap"): | |
is_inside = ( | |
pred["keypoints"] + 0.5 < np.array([image_np.shape[-2:][::-1]]) | |
).all(-1) | |
pred = {k: v[is_inside] for k, v in pred.items()} | |
if self.conf.nms_radius is not None: | |
keep = filter_dog_point( | |
pred["keypoints"], | |
pred["scales"], | |
pred["oris"], | |
image_np.shape, | |
self.conf.nms_radius, | |
scores=pred.get("scores"), | |
) | |
pred = {k: v[keep] for k, v in pred.items()} | |
pred = {k: torch.from_numpy(v) for k, v in pred.items()} | |
if scores is not None: | |
# Keep the k keypoints with highest score | |
num_points = self.conf.max_keypoints | |
if num_points is not None and len(pred["keypoints"]) > num_points: | |
indices = torch.topk(pred["scores"], num_points).indices | |
pred = {k: v[indices] for k, v in pred.items()} | |
return pred | |
def _forward(self, data: dict) -> dict: | |
image = data["image"] | |
if image.shape[1] == 3: | |
image = rgb_to_grayscale(image) | |
device = image.device | |
image = image.cpu() | |
pred = [] | |
for k in range(len(image)): | |
img = image[k] | |
if "image_size" in data.keys(): | |
# avoid extracting points in padded areas | |
w, h = data["image_size"][k] | |
img = img[:, :h, :w] | |
p = self.extract_single_image(img) | |
pred.append(p) | |
pred = { | |
k: torch.stack([p[k] for p in pred], 0).to(device) for k in pred[0] | |
} | |
if self.conf.rootsift: | |
pred["descriptors"] = sift_to_rootsift(pred["descriptors"]) | |
pred["descriptors"] = pred["descriptors"].permute(0, 2, 1) | |
pred["keypoint_scores"] = pred["scores"].clone() | |
return pred | |