This is my final analysis of my first attempt of creating super resolution images using post processing. I tried increasing resolution four, nine, and 16 fold.
DESCRIPTION:
The process is comprised of two parts:
The first consists of capturing many handheld frames, holding the camera as still as possible, This to provide the raw data to increase the resolution. The very slight unintentional movement of your hands and camera providing that data. The frames all have the same f-stop and shutter speed. The collection of the images takes a few seconds of high frame rate capture after setting the camera to manual.
The second is a six step post process that loads the multiple images as layers, resizes the image size to accommodate the increase in pixel count, align the layers, average the layers, flatten the layers, and sharpen the image. This is followed by all other processing such as sharpening or cropping.
LIMITATIONS
I found that I could not hold the camera still long enough to capture more than 21 near identical images. That is based on three image gathering attempts. I do have a slight tremor problem. However on my test day it was at a minimum. Given my best day before the tremors, I would not have been able hold still for 30 images. Processing time (mine and computer) is about an hour to a 4X image, about seven for a 9X image, and overnight for a 16X image. My computer is an Intel I7 with 16 gigabytes of memory and relatively high speed disks. The scratch disk is physically different the program and file storage disk.
PROS:
The 4X super resolution with 21 frames and layers, provided an excellent increase in sharpness far superior to standard, 9X, and 16X resolution. One hour of processing time is a small investment for the increased resolution. The 4X processing did not require paging of my computer's memory and intermediate file saves could be made at every step.
CONS:
A quick extrapolation for the number of the near identical images required for 9X and 16X resolutions would be almost 50 for 9X and 80 for 16X. I would find that impossible to achieve. The processing time would jump to near astronomical amounts. The 21 layered 9X and 16X attempts required paging. The 21 layered 9X and 16X intermediate step file save were impossible because the working file exceeded 2 gigabytes. Elements in the picture frame that moved during image collection were blurred or repeated.
RESULTS:
The 21 layer 4X super resolution image had resolution superior to the 21 layer 9X, 16X, and standard resolution. At first glance the 9X, 16X, and standard resolution appear to have the same sharpness at equal image sizes (16X 50%, standard res 200%, 9X 67%), however pixilation can only be seen on the standard resolution at those enlargements. I think that the 9X might be slightly better than the 16X and standard resolutions. All the super resolution images were created from the same 21 set of pictures/layers. The standard resolution is just one of those picture layers. In other words the same data was used for all.
I have presented a jpeg image of a detail of static and moving elements below. The details show equal image size. The 16X at 50% enlargement is first, normal at 200% enlargement is second, 4X at 100% enlargement is third, 9X at 67% enlargement is fourth. All are enlarged to the same size. There are two items to observe in each detail. The first is the bridge itself, particularly the post finials and the hand rail. The good trait, sharpness, can be judged from those. The bad trait, element movement, can be seen in examining the yellow/orange thin willow branch just below where it crosses the bridge deck. Look in the lower left hand portion of the image in black space beneath the deck. A single willow branch and splits into two at the lowest element. It is portrayed as a single branch in the standard res, as two in the 4X, five in the 9X, and two in the 16X.
CONCLUSION:
Given the difficulty in capturing more than 20 identical handheld images and the extreme process time for super resolution images greater than 4X, 4X super resolution is the greatest super resolution I would use. The image capture for 4X and one hour processing time are within my comfort zones. I imagine using this technique for hardscape landscapes on a regular basis.
IMAGE DETAIL:
16X at 50% enlargement, normal at 200% enlargement, 4X at 100% enlargement, 9X at 67% enlargement