ImageGear for C and C++ on Windows v21.0 - Updated
API Reference Guide / Core Component API Reference / Core Component Functions Reference / Image Processing Functions / IG_IP_detect_area_with_threshold
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    IG_IP_detect_area_with_threshold
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    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.