Access control to computer resource

A computer program product, comprising:

• a non-transitory computer readable storage medium readable by a processing circuit and storing instructions for performing a method comprising:
• providing a visual test to regulate access to a computer resource in response to a request by a user to access the computer resource, the visual test exploiting visual retention of the user within a period of time, the providing comprising:
• obtaining an image;
• segmenting the image into a plurality of parts and generating a plurality of figures using the plurality of parts of the image, each figure of the plurality of figures comprising at least one respective part of the plurality of parts of the image, wherein a portion of at least one figure of the plurality of figures overlaps with a portion of another figure of the plurality of figures;
• compiling the plurality of figures as a group of figures to be displayed in a sequence of figures;
• combining at least two figures of the plurality of the figures into a subgroup of the group of figures, the subgroup comprising adjacent parts of the plurality of parts of the image, wherein the subgroup comprises the one figure of the plurality of figures with the portion also repeated within the another figure of the plurality of figures and the another figure of the plurality of figures;
• and
• displaying, in the sequence, the figures of the group of figures to the user at a certain rate, the certain rate enabling the user to visually recognize the image from the plurality of figures with the plurality of parts of the image based, in part, on the portion of the one figure of the plurality of figures being overlapped with the portion of the another figure of the plurality of figures.