ImageGear for C and C++ on Windows v19.1 - Updated
IG_REC_image_preprocess
API Reference Guide > Recognition Component API Reference > Recognition Component Functions Reference > Recognition Image Preprocessing Functions > IG_REC_image_preprocess

Performs a series of image pre-processing steps by activating the IG_REC_PID_IMGPREPROCESS process.

Declaration:

 
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AT_ERRCOUNT ACCUAPI IG_REC_image_preprocess(
   HIG_REC_IMAGE hImage
);

Arguments:

Name Type Description
hImage HIG_REC_IMAGE Handle of the image.

Return Value:

Returns the number of ImageGear errors that occurred during this function call.

Supported Raster Image Formats:

See IG_REC_image_import.

Example:

 
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AT_ERRCOUNT ErrCount = 0;
HIGEAR higImage = 0;
HIG_REC_IMAGE higRecImage = 0;

ErrCount += IG_load_file("Image.tif", &higImage);
ErrCount += IG_REC_image_import(higImage, &higRecImage);
ErrCount += IG_REC_image_preprocess(higRecImage);

//...

ErrCount += IG_REC_image_delete(higRecImage);
ErrCount += IG_image_delete(higImage);

Remarks:

Performing these image pre-processing steps may improve the quality of the image from an OCR point of view, which may have an impact on the overall recognition accuracy for the page.

If pre-processing is desired, it should be done before performing auto-zoning and recognition. The available pre-processing steps are image inversion, deskewing, and rotation. The resulting modified images are available to the recognition engine and the application.

Whether and how it does these steps depends on the settings found in IG_REC_deskew_mode_set and IG_REC_orientation_mode_set.

The value needed for programmed deskewing (IG_REC_IMG_DESKEW_SET) can be detected by IG_REC_image_skew_detect and defined in IG_REC_slope_set.

Under certain circumstances, image despeckling is also performed internally. These depend on the settings found in IG_REC_despeckle_mode_set.

See Also

HIG_REC_IMAGE