Systems and techniques for masking non-public content in screen images are provided. An example system includes a screen capture tool, a region-based object detection system, a classifier, and an image masking engine. The screen capture tool may be configured to generate a screen image representing a screen being displayed by the system. The region-based object detection system may be configured to identify multiple regions within the screen image as potential non-public content regions. The classifier may be configured to selectively classify the identified regions as non-public content regions. The image masking engine may be configured to generate a masked image by masking the regions classified as non-public content regions in the screen image.