ImageGear for C and C++ on Linux v20.0 - Updated
API Reference Guide > Core Component API Reference > Core Component Functions Reference > Image Channel Functions > IG_image_channel_copy_create

This function creates a new image by copying a single channel from an existing image.


Copy Code
AT_ERRCOUNT ACCUAPI IG_image_channel_copy_create(
        LPCAT_CHANNEL_REF source,
        LPAT_CHANNEL_REF copy


Name Type Description
source LPCAT_CHANNEL_REF Location of source channel to copy.
copy LPAT_CHANNEL_REF Location of new image with copied 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++.


Copy Code
/* Extract the first alpha channel if one exists */
/* Otherwise, extract the first color channel */
AT_ERRCOUNT nErrcount;  /* Number of errors on stack */
HIGEAR hImage;          /* Handle of source image */
AT_CHANNEL_REF srcChan; /* Channel to copy */
AT_CHANNEL_REF dstChan; /* New image with copied channel */
enumIGColorSpaceIDs cs; /* Source image's color space */
AT_INT nColorChannels;  /* Number of color channels */
nErrcount = IG_load_file("alpha.tif", &hImage);
nErrcount = IG_image_colorspace_get(hImage, &cs);
nColorChannels = IG_util_colorspace_color_count_get(cs);
srcChan.hImage = hImage;
if (IG_util_colorspace_contains_alpha(cs))
    srcChan.uNumber = nColorChannels; /* First alpha channel */
    srcChan.uNumber = 0; /* First color channel */
nErrcount = IG_image_channel_copy_create(&srcChan, &dstChan);
hCopy = dstChan.hImage;
nErrcount = IG_save_file(dstChan.hImage, "alpha.bmp", 
nErrcount = IG_image_delete(hImage);


Specify in source the image and channel index to copy. If the copy is successful, copy will contain the HIGEAR handle of a newly allocated image containing the copied channel. The channel index in copy will always be set to 0. You are responsible for freeing the new image with IG_image_delete.

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