Steganography is an important area of research in recent years involving a number of applications. It is the science of embedding information into the cover image viz., text, video, and image (payload) without causing statistically significant modification to the cover image. The modern secure image steganography presents a challenging task of transferring the embedded information to the destination without being detected.This paper deals with hiding text in an image file using Least

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... Bit (LSB) based Steganography, Discrete Cosine Transform (DCT) based Steganography and Discrete Wavelet Transform (DWT) based steganography.The LSB algorithm is implemented in spatial domain in which the payload bits are embedded into the least significant bits of cover image to derive the stego-image whereas DCT & DWT algorithm are implemented in frequency domain in which the stego-image is transformed from spatial domain to the frequency domain and the payload bits are embedded into the frequency components of the cover image.The performance and comparison of these three techniques is evaluated on the basis of the parameters MSE, PSNR, Capacity & Robustness. I. Algorithm of steganography 4.1 LSB Based Steganography:[12] Algorithm to embed text message:- Step 1: Read the cover image and text message which is to be hidden in the cover image. Step 2: Convert text message in binary. Step 3: Calculate LSB of each pixels of cover image. Step 4: Replace LSB of cover image with each bit of secret message one by one. Step 5: Write stego image Step 6: Calculate the Mean square Error (MSE), Peak signal to noise ratio (PSNR) of the stego image. Algorithm to retrieve text message:- Step 1: Read the stego image. Step 2: Calculate LSB of each pixels of stego image. Step 3: Retrieve bits and convert each 8 bit into character. DCT Based Steganography:[12] Algorithm to embed text message:- Step 1: Read cover image. Step 2: Read secret message and convert it in binary. Step 3: The cover image is broken into 8×8 block of pixels. Step 4: Working from left to right, top to bottom subtract 128 in each block of pixels. Step 5: DCT is applied to each block. Step 6: Each block is compressed through quantization table. Step 7: Calculate LSB of each DC coefficient and replace with each bit of secret message. Step 8: Write stego image. Step 9: Calculate the Mean square Error (MSE), Peak signal to noise ratio (PSNR) of the stego image. Algorithm to retrieve text message:- Step 1: Read stego image. Step 2: Stego image is broken into 8×8 block of pixels. Step 3: Working from left to right, top to bottom subtract 128 in each block of pixels. Step 4: DCT is applied to each block. Step 5: Each block is compressed through quantization table. Step 6: Calculate LSB of each DC coefficient. Step 7: Retrieve and convert each 8 bit into character. DWT Based Steganography: Algorithm to retrieve text message:- Step 1: Read the cover image and text message which is to be hidden in the cover image. Step 2: Convert the text message into binary. Apply 2D-Haar transform on the cover image. Step 3: Obtain the horizontal and vertical filtering coefficients of the cover image. Cover image is added with data bits for DWT coefficients. Step 4: Obtain stego image. Step 5: Calculate the Mean square Error (MSE), Peak signal to noise ratio (PSNR) of the stego image.