A frame level noise estimate for an image can be determined. An image processor includes a high pass filter unit configured to perform high-pass spatial filtering of image data for first and second frames to produce high-pass spatially filtered information for the first frame and the second frame. A cumulative histogram generator is configured to analyze the high-pass spatially filtered information for the first frame and the second frame to produce a first cumulative histogram for the first frame and a second cumulative histogram for the second frame. A comparator is configured to determine a difference value between the first and second cumulative histograms. A mapping unit is configured to determine an estimated noise value based on the difference value.