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_convert_to_gray
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    IG_IP_convert_to_gray
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    This function converts the image referenced by hIGear to a grayscale image.

    Declaration:

     
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    AT_ERRCOUNT ACCUAPI IG_IP_convert_to_gray( HIGEAR hIGear);
    

    Arguments:

    Name Type Description
    hIGear HIGEAR HIGEAR handle of image.

    Return Value:

    Returns 0 if successful. Otherwise, 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++.

    Sample:

    Color, Image Processing, FlashPix, FreqIP, Color

    Example:

     
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    HIGEAR hIGear;            // HIGEAR handle of the image
    AT_ERRCOUNT nErrcount;    // Count of errs on stack upon ret from func
    
    // Load image file "picture.bmp" from working directory
    nErrcount = IG_load_file("picture.bmp", &hIGear);
    if(nErrcount == 0)
    {
        nErrcount = IG_IP_convert_to_gray(hIGear);
        // ...
        // Destroy the image
        IG_image_delete(hIGear);
    }
    

    Remarks:

    The function changes image color space to IG_COLOR_SPACE_ID_Gy. The bit depth of the resulting image will be equal to the maximal channel depth of the source image. If the original image has an Alpha or Pre-multiplied Alpha channel, the image will be blended over a black background to produce the resulting image. If the original image has Extra channels, they will be removed.