ImageGear for C and C++ on Windows v19.10 - Updated
IG_IP_detect_area_with_threshold
API Reference Guide > Core Component API Reference > Core Component Functions Reference > Image Processing Functions > IG_IP_detect_area_with_threshold

Detects an area of pixels using a specified threshold.

Declaration:

 
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AT_ERRCOUNT ACCUAPI IG_IP_detect_area_with_threshold(
        HIGEAR  hIGear, 
        AT_INT  xPos, 
        AT_INT  yPos,
        AT_DOUBLE nThreshold,
        LPAT_RECT lpRect, 
        AT_NR_ROI_MASK* lpMask
);

Arguments:

Name Type Description
hIGear HIGEAR Image to analyze.
xPos AT_INT X coordinate of a point inside the area to be detected.
yPos AT_INT Y coordinate of a point inside the area to be detected.
nThreshold AT_DOUBLE Area threshold.
lpRect LPAT_RECT Rectangular area to apply the effect to, or NULL for whole image.
lpMask AT_NR_ROI_MASK* Returns the ROI mask.

Return Value:

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

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++, except:
Indexed RGB – 1 bpp;
Indexed RGB with non-grayscale palette;
Grayscale – 1 bpp;
Images that have a Grayscale LUT attached to them.

Remarks:

The pixel is supposed to be in the area if the following condition is true for all pixel channels:

(pixel[i] >= initialPixel[i] - threshold) && (pixel[i] <= initialPixel[i] + threshold)

The area being detected is saved as the ROI of the page.