Using the Curvemeister Histogram or Composite window to set the highlight and shadow points and using them to set the appearance threshold.

This technique is used most frequently when there is no clear shadow or highlight in the scene.  By using the Curvemeister tools to show highlight and shadow areas on the actual image.  This allows you to see very quickly if you have the brightest highlight or darkest shadow in your images.

Analysis:

Let’s do a brief analysis of the above image and see what things we can improve on.

Overall the image looks flat, it is underexposed and the colors look muted.
We can see some areas we need to be interested in:

1.There are some specular highlights on the bee. There are also specular highlights on the tips of the spikes in the cone flower.

2.There are shadows in the image that appear to have detail in them but it is unclear if the detail is even recoverable at this point.

3.This appears to be a brightly lit colorful image.  The muted greens and oranges can be improved.

This is common approach to many images.  Take a minute to look at the problem areas and start thinking about how you can improve these areas.

Process:

To begin the process of thresholding you need to open the Curvemeister tool.  The example below is in the LAB color space with the histogram showing the pixels in the image.

Right Click on the image in what you think is the brightest highlight.  From the menu choose “Set Highlight”

This will set a mark onto the image as shown below

This is the “highlight point”.  This is the marker point you will be dragging around the image to verify your placement of the highlight.

Left Click on the Marker point and drag it around the image.

You will see the image break up into a high contrast mask that allows you to see pixels with values higher <Bright areas>
and lower <Dark areas> than the current pixels under the marker.

Adjust the position of the marker until you see an image similar to the one shown.  There are very few points brighter than the ones shown under the marker.  You can try to eliminate all of the white dots but you will end up frustrated.  Just try to get rid of most of them.

Image after “highlight thresholding” using the set highlight marker.

Now let’s set the shadow.

Right Click on the image in a shadow area and choose “Set Shadow”

Left click on the “shadow point” and drag it around the image.

You will see the image break up into another high contrast mask. 


Attempt to remove all the black you can from the image.


Notice that the black in the bee is not the darkest shadow in the image.
Black can be an illusion when it comes to pixel values.

Here is the Image with the highlight and shadow values set.  All the bee needs now is some saturation and we should have a very interesting repair for this image.
Because this image is being adjusted in LAB we can use the saturation slider to add color saturation to the image.

Finished using only the saturation slider in LAB.