ImageGear for C and C++ on Windows v21.0 - Updated
API Reference Guide / Core Component API Reference / Core Component Functions Reference / Image Channel Functions / IG_image_channel_update
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    IG_image_channel_update
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    This function copies pixel data from one channel to another channel.

    Declaration:

     
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    AT_ERRCOUNT ACCUAPI IG_image_channel_update(
            LPCAT_CHANNEL_REF channelToUpdateWith,
            LPCAT_CHANNEL_REF channelToBeUpdated
    );
    

    Arguments:

    Name Type Description
    channelToUpdateWith LPCAT_CHANNEL_REF Channel to use as source channel.
    channelToBeUpdated LPCAT_CHANNEL_REF Channel to be replaced by source channel.

    Return Value:

    Returns the number of ImageGear errors that occurred during this function call. If there are no errors, the return value is IGE_SUCCESS.

    Supported Raster Image Formats:

    All pixel formats supported by ImageGear for C and C++.

    Sample:

    None

    Example:

     
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    /* Alter a 24-bit RGB image to use the red channel data 
    for both red and blue channels */
    AT_ERRCOUNT nErrcount;  /* Number of errors on stack */
    HIGEAR hImage;          /* Handle of source image */
    AT_CHANNEL_REF chanSrc; /* Channel to update from */
    AT_CHANNEL_REF chanDst; /* Channel to update */
    nErrcount = IG_load_file("test.jpg", &hImage);
    chanSrc.hImage = hImage;
    chanSrc.uNumber = 0;
    chanDst.hImage = hImage;
    chanDst.uNumber = 2;
    nErrcount = IG_image_channel_update(&chanSrc, &chanDst);
    nErrcount = IG_save_file(hImage, "test.bmp", 
        IG_SAVE_BMP_UNCOMP);
    IG_image_delete(hImage);
    

    Remarks:

    Each channel is specified by a HIGEAR image handle and the channel's index within that image. The source and destination channels can reside in different images or the same image.