The widespread diffusion of synthetically generated content is a serious threat that needs urgent countermeasures. As a matter of fact, the generation of synthetic content is not restricted to multimedia data like videos, photographs or audio sequences, but covers a significantly vast area that can include biological images as well, such as western blot and microscopic images. In this paper, we focus on the detection of synthetically generated western blot images. These images are largely explored in the biomedical literature and it has been already shown they can be easily counterfeited with few hopes to spot manipulations by visual inspection or by using standard forensics detectors. To overcome the absence of publicly available data for this task, we create a new dataset comprising more than 14K original western blot images and 24K synthetic western blot images, generated using four different state-of-the-art generation methods. We investigate different strategies to detect synthetic western blots, exploring binary classification methods as well as one-class detectors. In both scenarios, we never exploit synthetic western blot images at training stage. The achieved results show that synthetically generated western blot images can be spot with good accuracy, even though the exploited detectors are not optimized over synthetic versions of these scientific images. We also test the robustness of the developed detectors against post-processing operations commonly performed on scientific images, showing that we can be robust to JPEG compression and that some generative models are easily recognizable, despite the application of editing might alter the artifacts they leave.
翻译:合成成像的广泛传播是一个严重威胁,需要紧急对策。事实上,合成成像内容的生成并不局限于视频、照片或音频序列等多媒体数据,而是涵盖一个巨大的领域,其中也包括生物图像,例如西方的色素和微型图像。在本文中,我们侧重于探测合成成像产生的西方色素图像。这些图像在生物医学文献中广泛探讨,已经表明它们很容易被伪造,很少希望通过目视检查或使用标准的法医探测器来发现操纵。为了克服缺乏用于这项任务的公开数据,我们创建了一套新数据集,由超过14K的原始西方色素图像和24K的合成西方色素图像组成,这些图像使用四种不同的最先进的生成方法生成。我们调查不同的战略以探测合成西方色素,探索二元分类方法以及一等探测器。在这两种情况下,我们从未在培训阶段利用合成的西方色素图像。取得的结果表明,合成成色的西方色图像可以以良好的准确度被识别出来,即使利用的西方色素图像和24K合成西方合成的西方色素图像是我们所制作的,我们所制作的精度探测器也能够优化地展示这些精度。