Conventional steganography methods fabricate the secret information into the cover pixels without analyzing the pixel intensities of an image. As a result, some minor pixel level manipulations may lead to huge visual distortion in the stego-image. To this end, in this paper, a novel steganographic scheme based on Kirsch edge detector is proposed. The aim of the scheme is to maximize the payload by embedding more secret bits into edge pixels and fewer bits into the non-edge pixels. The proposed scheme has three major phases: construction of edge image, embedding and extraction. The first phase deals with the construction of masked image from the cover image, and in turn, edge image from the masked one. The second phase deals with the decomposition of the cover image into a set of triplet of pixels and then embedding of (x + y + 1) bits of secret data into each triplet of pixels to obtain the stego-image. Here, ‘x’ and ‘y’ are not fixed as the edge information of each triplet changes incessantly. The third or last phase deals with the extraction of the secret information from the stego-image using the reverse process. Simulation results on some standard images ensure that the proposed method achieves higher payload and better image quality compared to the conventional steganographic schemes. Furthermore, the Kirsch edge detector is able to produce more number of edge pixels compared to the traditional edge detectors; and, hence the proposed scheme also outperforms the existing edge-based methods in terms of payload.

中文翻译：

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基于Kirsch边缘检测的图像隐写术

传统的隐写术方法在不分析图像的像素强度的情况下将秘密信息编造到覆盖像素中。因此，一些小的像素级操作可能会导致隐写图像中的巨大视觉失真。为此，本文提出了一种基于Kirsch边缘检测器的新型隐写方案。该方案的目的是通过在边缘像素中嵌入更多的秘密位和在非边缘像素中嵌入更少的位来最大化有效载荷。所提出的方案包括三个主要阶段：边缘图像的构建、嵌入和提取。第一阶段处理从封面图像构建蒙版图像，然后从蒙版图像构建边缘图像。第二阶段处理将覆盖图像分解为一组像素三元组，然后将 (x + y + 1) 位秘密数据嵌入到每个像素三元组中以获得隐写图像。这里，'x' 和 'y' 不是固定的，因为每个三元组的边缘信息不断变化。第三个或最后一个阶段处理使用反向过程从隐写图像中提取秘密信息。在一些标准图像上的仿真结果确保了所提出的方法与传统的隐写方案相比实现了更高的有效载荷和更好的图像质量。此外，与传统的边缘检测器相比，Kirsch 边缘检测器能够产生更多数量的边缘像素；因此，所提出的方案在有效载荷方面也优于现有的基于边缘的方法。