1. A method for OCR-processing of a frame in a video source, the method comprising: receiving by a hardware processor the frame from the video source; retrieving from a memory prior frame data associated with the video source; and performing by the hardware processor OCR-processing of at least a portion of the frame to detect one or more text strings, wherein the OCR-processing of the portion of the frame includes at least one of: using the prior frame data to detect in the portion of the frame at least one blob similar to at least one blob described in the prior frame data; using at least one blob similar to at least one blob described in the prior frame data to detect in the portion of the frame at least one character candidate similar to at least one character candidate described in the prior frame data; using at least one character candidate similar to at least one character candidate described in the prior frame data to detect in the portion of the frame at least one text candidate similar to at least one text candidate described in the prior frame data; and using at least one text candidate similar to at least one text candidate described in the prior frame data to detect in the portion of the frame at least one text string similar to at least one text string described in the prior frame data.