Typically, metadata of images are stored in a specific data segment of the image file. However, to securely detect changes, data can also be embedded within images. This follows the goal to invisibly and robustly embed as much information as possible to, ideally, even survive compression. This work searches for embedding principles which allow to distinguish between unintended changes by lossy image compression and malicious manipulation of the embedded message based on the change of its perceptual or robust hash. Different embedding and compression algorithms are compared. The study shows that embedding a message via integer wavelet transform and compression with Karhunen-Loeve-transform yields the best results. However, it was not possible to distinguish between manipulation and compression in all cases.

翻译：通常，图像元数据存储在图像文件的特定数据段中。然而，为安全地检测篡改，数据也可嵌入图像内部。此方法的目标是以不可见且鲁棒的方式嵌入尽可能多的信息，理想情况下甚至能抵抗压缩。本研究探索嵌入原则，通过感知哈希或鲁棒哈希的变化，区分有损图像压缩导致的非预期改变与针对嵌入消息的恶意篡改。研究比较了不同的嵌入和压缩算法。结果表明，通过整数小波变换嵌入消息并结合Karhunen-Loeve变换进行压缩可获得最佳效果。但并非在所有情况下都能区分篡改与压缩。