SIFT
import { SIFT } from '@banou/opencv-wasm'Use after await initOpenCV(). See the initialization and named imports guide.
Native object: release it with using or delete(). Factories can return null; check before calling methods. Inherits Feature2D.
Class for extracting keypoints and computing descriptors using the Scale Invariant Feature Transform (SIFT) algorithm by D. Lowe [Lowe04] .
Constructors and members
static create
Note: The contrast threshold will be divided by nOctaveLayers when the filtering is applied. When nOctaveLayers is set to default and if you want to use the value used in D. Lowe paper, 0.03, set this argument to 0.09.
create(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number, sigma: number, enable_precise_upscale: boolean): SIFT | null;7 available overloads
create(): SIFT | null;create(nfeatures: number): SIFT | null;create(nfeatures: number, nOctaveLayers: number): SIFT | null;create(nfeatures: number, nOctaveLayers: number, contrastThreshold: number): SIFT | null;create(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number): SIFT | null;create(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number, sigma: number): SIFT | null;create(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number, sigma: number, enable_precise_upscale: boolean): SIFT | null;nfeaturesThe number of best features to retain. The features are ranked by their scores (measured in SIFT algorithm as the local contrast)
nOctaveLayersThe number of layers in each octave. 3 is the value used in D. Lowe paper. The number of octaves is computed automatically from the image resolution.
contrastThresholdThe contrast threshold used to filter out weak features in semi-uniform (low-contrast) regions. The larger the threshold, the less features are produced by the detector.
edgeThresholdThe threshold used to filter out edge-like features. Note that the its meaning is different from the contrastThreshold, i.e. the larger the edgeThreshold, the less features are filtered out (more features are retained).
sigmaThe sigma of the Gaussian applied to the input image at the octave #0. If your image is captured with a weak camera with soft lenses, you might want to reduce the number.
enable_precise_upscaleWhether to enable precise upscaling in the scale pyramid, which maps index
\texttt{x}to\texttt{2x}. This prevents localization bias. The option is disabled by default.
The SIFT | null result.
static create1
Create SIFT with specified descriptorType.
Note: The contrast threshold will be divided by nOctaveLayers when the filtering is applied. When nOctaveLayers is set to default and if you want to use the value used in D. Lowe paper, 0.03, set this argument to 0.09.
create1(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number, sigma: number, descriptorType: number, enable_precise_upscale: boolean): SIFT | null;2 available overloads
create1(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number, sigma: number, descriptorType: number): SIFT | null;create1(nfeatures: number, nOctaveLayers: number, contrastThreshold: number, edgeThreshold: number, sigma: number, descriptorType: number, enable_precise_upscale: boolean): SIFT | null;nfeaturesThe number of best features to retain. The features are ranked by their scores (measured in SIFT algorithm as the local contrast)
nOctaveLayersThe number of layers in each octave. 3 is the value used in D. Lowe paper. The number of octaves is computed automatically from the image resolution.
contrastThresholdThe contrast threshold used to filter out weak features in semi-uniform (low-contrast) regions. The larger the threshold, the less features are produced by the detector.
edgeThresholdThe threshold used to filter out edge-like features. Note that the its meaning is different from the contrastThreshold, i.e. the larger the edgeThreshold, the less features are filtered out (more features are retained).
sigmaThe sigma of the Gaussian applied to the input image at the octave #0. If your image is captured with a weak camera with soft lenses, you might want to reduce the number.
descriptorTypeThe type of descriptors. Only CV_32F and CV_8U are supported.
enable_precise_upscaleWhether to enable precise upscaling in the scale pyramid, which maps index
\texttt{x}to\texttt{2x}. This prevents localization bias. The option is disabled by default.
The SIFT | null result.
clone
Create another handle to the same native object. This retains the object without copying its pixels or algorithm state; dispose both handles separately.
clone(): this;The this result.
getDefaultName
Returns the algorithm string identifier. This string is used as top level xml/yml node tag when the object is saved to a file or string.
getDefaultName(): string;The string result.
setNFeatures
Set the nfeatures used by this SIFT object.
setNFeatures(maxFeatures: number): void;maxFeaturesmax features argument (number).
getNFeatures
Return the nfeatures configured on this SIFT object.
getNFeatures(): number;The number result.
setNOctaveLayers
Set the noctave layers used by this SIFT object.
setNOctaveLayers(nOctaveLayers: number): void;nOctaveLayersn octave layers argument (number).
getNOctaveLayers
Return the noctave layers configured on this SIFT object.
getNOctaveLayers(): number;The number result.
setContrastThreshold
Set the contrast threshold used by this SIFT object.
setContrastThreshold(contrastThreshold: number): void;contrastThresholdcontrast threshold argument (number).
getContrastThreshold
Return the contrast threshold configured on this SIFT object.
getContrastThreshold(): number;The number result.
setEdgeThreshold
Set the edge threshold used by this SIFT object.
setEdgeThreshold(edgeThreshold: number): void;edgeThresholdedge threshold argument (number).
getEdgeThreshold
Return the edge threshold configured on this SIFT object.
getEdgeThreshold(): number;The number result.
setSigma
Set the sigma used by this SIFT object.
setSigma(sigma: number): void;sigmasigma argument (number).
getSigma
Return the sigma configured on this SIFT object.
getSigma(): number;The number result.
These signatures describe this package. Upstream documentation can mention optional backends that are absent from this build. Check runtime compatibility before choosing a backend or file format.