Comparative Analysis of Image From Modification of Steganography Method in Protecting Text Messages From Image Compression Reno Adhi Perwira (a*), Silvester Dian Handy Permana (a), Yaddarabullah (a)
a) Program Studi Teknik Informatika, Universitas Trilogi
Jl.TMP Kalibata No.1, Jakarta 12760, Indonesia
*renoperwira[at]trilogi.ac.id
Abstract
One of the commonly used steganographic methods is the Least Significant Bit (LSB) method. The technical insertion in the LSB method and the RPP method have similar weaknesses, if the stego image experiences image compression above 5% pixels per inch (ppi), the secret message in the stego image cannot be extracted. There are alternatives to cover the gap, namely by modifying the LSB and RPP methods with the Redundant Pattern Encoding (RPE) method. The RPE method can duplicate the stego image or secret message that will be hidden. Those modifications will produce two patches called Patch A and Patch B, where the insertion of message bits will be done on both patches. Stego images from the modification of the steganography method will be compressed using the LZW and Huffman algorithm. The compressed stego image will be decompressed to return the stego image to its original image format. The results of this research indicate that the stego image that has been compressed and decompressed using the LZW and Huffman methods has been successfully extracted with a character emergence ratio value of 100%. Stego images that have been compressed using LZW will produce a compression ratio of 0.606 to 1.471, while stego image compressed with huffman will produce a compression ratio of 0.593 to 1,016.
Keywords: Least Significant Bit, Random Pixel Positioning, Redundant Pattern Encoding, Patch, Stego Image, LZW, Huffman
