The problem of extracting blindly data embedded over a wide band in a spectrum domain of digital medium image is considered. Multicarrier Iterative Generalized Least Square (M-IGLS) algorithm is develop to extract unknown data hiding in the host via multicarrier SS embedding. Original host and embedding carriers are not need to be known. This project consider the blind extraction technique. Which means original host and embedding carriers are assumed unavailable. The hidden data which is embedded in the image to the host signal via multicarrier SS embedding. The hidden data is extracted from image. Multicarrier Iterative Generalized Least Square (M-IGLS) algorithm is the extraction algorithm is used to extract the hidden data from image. M-IGLS is low complexity algorithm which provides high performance. Experimental studies on image show that the developed algorithm can achieve recovery probability of error equals to what may be attained with known embedding carriers and original host.