With our Optipix software, Photographers get state-of-the art image processing from the moment photos are captured to the time they're printed.
Whether from a digital camera that records Camera RAW images, Scanned negatives, or any other source, it is important to start with the best image that you can get.
Although you may not see the difference between a 16-bit image and an 8-bit image, these differences can cause serious problems and limitations to subsequent processing and printing. The tools that you use on your images need to be able to work with the images that you spent so much time and trouble getting.
Photoshop’s 8-bit (256-wide) histogram
9-bit (512-wide) histogram shows that there are fine details in the image not apparent in an 8-bit image.
Click here - for a 10-bit (1024-wide) histogram
One of the challenges with transparency and especially digital images is Dynamic Range. Film cameras have sensitivity to large brightness range, but that is not true for their digital cousins. For a scene that isn’t changing it is possible to bracket a series of images (e.g. -1, 0, +1) and then blend them together to create one HDR or High Dynamic Range image.
Bright(ev+1) and dark(ev-1) source images
HDR Blended result
Let’s look at the histograms for these two images and see what actually happened.
Dark (ev-1) and Bright(ev+1)
These two images are combined and the overlapping areas are properly matched up. However, instead of clipping at the top (right histogram), we use the bright detail from the underexposed Dark image to fill in that area. The result is the histogram below:
Histogram of combined HDR image
Now, the good news is that you’ve captured both highlight and shadow detail.There is no clipping. The bad news is that the resulting image tends to look flat. There doesn’t seem to be that much contrast in the image.
Dynamic Range Compression to show bright and dark details at the same time
Through a process called Dynamic Range Compression, we can put more emphasis on the detail in the image and less on the absolute brightness. This resulting image shows both the detail in the clouds AND in the dark stonework. This is especially important when printing, and you can do it with Optipix.
This process works much better with Camera RAW images, but is actually pretty useful with high quality JPEG images, too. The only requirements are that you align two or more images (tripod suggested) and that your subject doesn’t move.
Often when taking a picture, it can be slightly out-of-focus. With the tiny preview screen on a digital camera it is impossible to tell if the subject is very sharp or not. Now, a preview screen is better than none at all (i.e. film cameras), you may not know whether the image was any good until you’re back at home looking at the picture on your big screen.
Original image - Refocus applied
This is the same Deconvolution technique that was applied to images from the Hubble. It is extremely powerful and can restore some degree of focus to a non-noisy high quality image.
Sharpening is not the same as refocusing. When we refocus an image we’re gather up light that was smeared out over an area and try to put it back into the source points or edges that it came from. Sharpening, on the other hard, is a way to emphasize the edges or details that are there. Ideally we want to do both: first the refocus step and then the sharpening step.
There are many kinds of sharpening tools, probably as many as there are programmers. Here are a few of the most popular ones:
|1. The Custom tool in Photoshop – An example of an Additive Laplacian. This is filter excellent at enhancing edges, but will also amplify noise||
|2. The UnSharp Mask tool in Photoshop – This is also an excellent tool for enhancing edges, but causes bad halos around objects and can blow out fine detail.||
|3. Edge Enhancer in Optipix – This enhances the edges in an image without amplifying the noise.||
|4. Detail Sharpener in Optipix – This enhances the detail without amplifying the edges and doesn’t create halos. (In this example, we used 300% emphasis on the detail to give an idea of how it works. We recommend a lower setting for normal use.) In a Camera RAW image, this detail is likely to be real. In a JPEG image, this detail is probably a JPEG artifact.||
There are really two kinds of contrast:
Local contrast that we enhance with various sharpening tools, dodging and burning.
Global contrast that we enhance the overall brightness of the image with things like Photoshop’s Levels and Curves functions.
What we’re really doing with Levels and Curves are stretching and compressing parts of the histogram, and clipping the ends that may not print well, or take up a lot of the available range.
Changing gamma on a histogram
Optipix has an AutoContrast function that lets you place the 50% point (the orange line, above) in whatever Zone you want and lets you see a much larger histogram than Levels can provide.
You can learn a lot more about optimizing an image from George DeWolfe. On the Optipix CD is his Digital Fine Print Workflow which discusses the whole process of getting an image through making a Digital Fine Print:
He makes effective use of layers in Photoshop and the functions in Optipix to make it easier to make a high quality print.
Every function in Optipix is completely scriptable and actionable. This means that you can make and record your own workflow to better optimize your time and your images.