An apparatus comprising: a processor; and memory coupled to the processor, the memory comprising executable instructions that, when executed by the processor, cause the processor to effectuate operations comprising: generating a masked reference image by applying a mask to a reference image of a scene, the masked reference image comprising a plurality of pixels of the reference image that fall outside the mask, wherein applying the mask excludes one or more objects within the reference image that change color or brightness and/or that move between the reference image and a second image; generating an exposure adjustment estimate for compensating a particular pixel value of pixels contained in the masked reference image by calculating, for each particular pixel value, the average of the differences of pixel values between pixels having said particular pixel value in the masked reference image and corresponding pixels in the second image of the scene, wherein a corresponding pixel in the second image corresponds to a pixel in the masked reference image when the two pixels represent the same part of the scene; and generating a compensated image portion of the reference image by adding the exposure adjustment estimate to the value of pixels that are both in a compensation portion of the reference image and also have pixel values equal to the particular pixel value. a processor; and memory coupled to the processor, the memory comprising executable instructions that, when executed by the processor, cause the processor to effectuate operations comprising: generating a masked reference image by applying a mask to a reference image of a scene, the masked reference image comprising a plurality of pixels of the reference image that fall outside the mask, wherein applying the mask excludes one or more objects within the reference image that change color or brightness and/or that move between the reference image and a second image; generating an exposure adjustment estimate for compensating a particular pixel value of pixels contained in the masked reference image by calculating, for each particular pixel value, the average of the differences of pixel values between pixels having said particular pixel value in the masked reference image and corresponding pixels in the second image of the scene, wherein a corresponding pixel in the second image corresponds to a pixel in the masked reference image when the two pixels represent the same part of the scene; and generating a compensated image portion of the reference image by adding the exposure adjustment estimate to the value of pixels that are both in a compensation portion of the reference image and also have pixel values equal to the particular pixel value. generating a masked reference image by applying a mask to a reference image of a scene, the masked reference image comprising a plurality of pixels of the reference image that fall outside the mask, wherein applying the mask excludes one or more objects within the reference image that change color or brightness and/or that move between the reference image and a second image; generating an exposure adjustment estimate for compensating a particular pixel value of pixels contained in the masked reference image by calculating, for each particular pixel value, the average of the differences of pixel values between pixels having said particular pixel value in the masked reference image and corresponding pixels in the second image of the scene, wherein a corresponding pixel in the second image corresponds to a pixel in the masked reference image when the two pixels represent the same part of the scene; and generating a compensated image portion of the reference image by adding the exposure adjustment estimate to the value of pixels that are both in a compensation portion of the reference image and also have pixel values equal to the particular pixel value.