GSK Class Reference


                    
                    
                    +initWithLicenseKey:error:

Must be called first with a valide license key to enable the SDK.

Warning

Important This method must be called before any use of the SDK methods.

All the SDK errors return proper errors in that case and you can handle them to ensure you provide a good degraded experience. For instance, you can prompt the user to update the application to use the scanning feature in case they use a version of the application with an expired license key.

Declaration

Objective-C

+ (BOOL)initWithLicenseKey:(nonnull NSString *)licenseKey
                     error:(NSError *_Nullable *_Nullable)error;

Swift

class func initWithLicenseKey(_ licenseKey: String) throws

Parameters

`licenseKey`	The license key
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

YES if the SDK was initialized successfully, NO if an error occured.


                    
                    
                    +detectQuadrangleFromImage:options:error:

Detects the quadrangle corresponding to the edges of a document in a photo

Declaration

Objective-C

+ (GSKQuadrangleDetectionResult *_Nullable)
    detectQuadrangleFromImage:(nonnull UIImage *)image
                      options:(GSKDetectQuadrangleOptions)options
                        error:(NSError *_Nullable *_Nullable)error;

Swift

class func detectQuadrangle(from image: UIImage, options: GSKDetectQuadrangleOptions = []) throws -> GSKQuadrangleDetectionResult

Parameters

`image`	The photo to detect a document in
`options`	See GSKDetectQuadrangleOptions
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

The detected quadrangle or nil if an error occured.


                    
                    
                    +detectQuadrangleFromSampleBuffer:error:

Detects the quadrangle corresponding to the edges of a document in video frame

Declaration

Objective-C

+ (GSKQuadrangleDetectionResult *_Nullable)
    detectQuadrangleFromSampleBuffer:(nonnull CMSampleBufferRef)sampleBuffer
                               error:(NSError *_Nullable *_Nullable)error;

Swift

class func detectQuadrangle(from sampleBuffer: CMSampleBuffer) throws -> GSKQuadrangleDetectionResult

Parameters

`sampleBuffer`	a YCbCr sample buffer of a video frame. Make sure the video output generating these frames is configured with the pixel format kCVPixelFormatType_420YpCbCr8BiPlanarFullRange
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

The detected quadrangle or nil if an error occured.


                    
                    
                    +warpImage:withQuadrangle:error:

Extracts the document from the given photo and corrects its perspective

Declaration

Objective-C

+ (UIImage *_Nullable)warpImage:(nonnull UIImage *)image
                 withQuadrangle:(GSKQuadrangle *_Nullable)quadrangle
                          error:(NSError *_Nullable *_Nullable)error;

Swift

class func warpImage(_ image: UIImage, with quadrangle: GSKQuadrangle?) throws -> UIImage

Parameters

`image`	The original photo
`quadrangle`	The quadrangle representing the edges of the document. If nil, the entire image is returned.
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

the cropped and perspective-corrected document or nil if an error occured. Errors include: - non-convex quadrangle - failure to warp


                    
                    
                    +bestFilterForImage:error:

Determines the best image processing type for a document

Declaration

Objective-C

+ (GSKBestFilterResult *_Nullable)
    bestFilterForImage:(nonnull UIImage *)image
                 error:(NSError *_Nullable *_Nullable)error;

Swift

class func bestFilter(for image: UIImage) throws -> GSKBestFilterResult

Parameters

`image`	The cropped and perspective-corrected document
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

The best enhancement for this document or nil if an error occured.


                    
                    
                    +enhanceImage:withFilter:error:

Enhances a document image with the selected post processing type

Declaration

Objective-C

+ (UIImage *_Nullable)enhanceImage:(nonnull UIImage *)image
                        withFilter:(GSKFilterType)filter
                             error:(NSError *_Nullable *_Nullable)error;

Swift

class func enhanceImage(_ image: UIImage, with filter: GSKFilterType) throws -> UIImage

Parameters

`image`	the warped, perspective-corrected document
`filter`	the enhancement filter to apply to the image. - see: GSKFilterType
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

the enhanced image or nil if an error occured.


                    
                    
                    +correctImageDistortion:error:

Corrects curvature distortion in the given image. This typically corrects curvature seen when scanning a book or when a receipt is folded.

This method is meant to be applied on a warped image.

Declaration

Objective-C

+ (UIImage *_Nullable)correctImageDistortion:(nonnull UIImage *)image
                                       error:
                                           (NSError *_Nullable *_Nullable)error;

Swift

class func correctImageDistortion(_ image: UIImage) throws -> UIImage

Parameters

`image`	the input image.
`error`	On input, a pointer to an error object. If an error occurs, this pointer is set to an actual error object containing the error information. You may specify nil for this parameter if you do not want the error information.

Return Value

the corrected image or nil if an error occured.