Frequency-Based Steganography Using 32x32 Interpolated Quantization Table and Discrete Cosine Transform

Image steganography is the art of hiding the existence of the information in the image. The steganography can be categorized into two types in spatial domain and frequency domain. In this study, the frequency based image steganography using Discrete Cosine Transformation (DCT) and JPEG is proposed. Instead of using 8x8-pixel blocks with the 8x8-pixel quantization table, a larger block of size 32x32 will be used with a corresponding 32x32 quantization table created by cubic interpolation technique. Our results show that we can reduce the computation time and increase the capacity of the secret messages while maintaining the image quality and the size of JPEG stego-image.