Description

The function lqr_carver_set_black_channel sets the black channel index of the image stored in the LqrCarver pointed to by carver to channel_index (between 0 and channels - 1, where channels is the number of colour channels of the carver).

Use a negative value for cahnnel_index to specify that no black channel is present.

If the specified channel coincides with the current value of the alpha channel, the alpha channel is unset.

Calling this function sets the image time of the carver to LQR_CUSTOM_IMAGE. Furthermore, the image color model will be assumed to be subtractive by the function lqr_rwindow_read(3) when it computes the brightness or the luma.

Return value

The return value follows the Liquid Rescale library signalling system.

See also

LqrImageType(3), lqr_carver_new(3), lqr_carver_set_image_type(3), lqr_carver_set_alpha_channel(3), lqr_carver_get_image_type(3), lqr_carver_get_channels(3)