1. A processor-implemented method for authorizing human access to complete an online transaction for a service over the Internet, comprising: a) detecting a request to enter information for the service, in response to the detection, i) identifying a first image for display at a receiver device, the first image defined to cover a display portion of a screen of the receiver device; ii) identifying a second image with a detectable trait, the second image configured for display over the first image; iii) executing a first delta-based analyzer to monitor changes of the first image; iv) executing a second delta-based analyzer to monitor changes of the second image, the changes of the second image include changes to the detectable trait; v) combining the changes to the first image and the second image to generate a plurality of combined frames in a framebuffer, the combined frames including frames representing the changes of the first image and frames representing the changes of the second image, the changes to the first and the second images being independently adjustable to a respective first and second display settings; b) transmitting the combined frames from the framebuffer to the receiver device for display; c) transmitting a query regarding the detectable trait of the second image to the receiver device; d) receiving a response from a user to the query at the receiver device; and e) enabling user input of the information for the service at the receiver device when the response to the query is determined to be successful.