![]() You can see the clone tool options and the brush ( Dialogs -> Brushes) I selected (at right). This gave me a similar light-dark-light transition. I cloned from the light part of the leaf just beyond the dark band to the right of the blown out area. A description of how to use this tool is beyond the scope of this document (see the GIMP savvy to find out more about this tool). We’ve lost these pixels entirely, so we’re going to have to graft some on from somewhere nearby using the clone tool. I used a value of 15 pixels or so in this case.įinally (important!), click back on the Layers tab and select the Background layer, so the selection and further operations will apply to the image and not the channel mask. Now feather the selection ( Select -> Feather). You may want to also click on the eye beside the channel to turn off visibility of the channel. Step 6 ¶Ĭlick on the Channels tab again, and right click on the new channel and select Channel to Selection ( Ctrl+S). Go back to the threshold image, Select -> All ( Ctrl+A) and Edit -> Copy ( Ctrl+C).Įdit -> Paste it into the original image (it should go into the new channel).Ĭlick on the Layers tab and anchor the floating selection. Click on the Channels tab and add a new channel by clicking on the new channel button. Go back to the original image, and bring up the Layers and Channels dialog ( Layers -> Layers, Channels & Paths, or Ctrl+L). This causes all the pixels in the image from 250-255 to go white and all the others to go black. Alternatively, you can type in the lower bound, as I did here (250). In the threshold dialog box, drag to select the very right (extreme highlights) portion of the histogram. In the duplicate, select Image -> Colors -> Threshold. I’ll use this for the main “pixel graft”.ĭuplicate the original image ( Image -> Duplicate or Ctrl+D). The first step is to create a channel mask to be able to mask out parts of the image we don’t want to affect. If there had been some detail left here I might have tried a variation on the contrast masking technique or the “digital” neutral density filter first. Using the color picker tool, you can see that there is no usable information left in the highlight. There are some less objectionable, but bothersome burned out areas to the lower right of the cat’s face. The worst and most noticable is the one off of the leaf at the top of the image. While it did a great job of exposing for the dark cat in the shade of the tree, there are several spots where specular reflections of the bright sunshine overhead blew out. ![]() The camera was set on automatic exposure. When I saw the image later on the monitor I realized what a nice natural three-dimensional frame I had. ![]() Thinking there might be an interesting shot there, I grabbed the camera and shot him from several angles, including this shot through a hole in the foliage. The basic technique is to graft matching areas of the image into the burned out parts using the clone tool and then to use several additional tools to blend the seams of the cloned areas. I find that if I treat my digital camera as if I were shooting slide film the exposure rules are about the same. With these kinds of cameras it is worth paying attention to the old adage: “expose for the highlights”. Many digital cameras have similar issues, especially consumer level ones. If you are not careful with your exposure you can easily lose all detail in your highlight areas, with no way to get it back: they “blow out” to clear (white). This is a problem that is familiar to photographers shooting transparency film, which has an effective contrast range of about 5 stops. In this tutorial I’ll show you how to salvage an image that has blown out highlights. Jeschke and may not be used without permission of the author. Text and images Copyright (C) 2002 Eric R. ![]()
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