The names of these algorithms come from academic papers in which they were described. Qtpfsgui uses implementations from the pfstools command-line package; to learn more you can consult the pfstools page linking to each paper.
The only real way to determine which algorithm produces the best results is to try them all. Qtpfsgui lets you generate previews for as many tests as you care to look at, at a number of sizes. On a slower system, it is a good idea to run a few samples at thumbnail size before you try to export any full-resolution output.
Figure 3 features several tone-mapped samples using different algorithms all at their default settings. As you can see, they vary considerably in effect and how natural they appear. Even on some of the most natural-looking, though, you can find odd-looking artifacts such as the halo effect around the curtains, and the black highlights on the arm and back of the sofa. It is also worth noting that because of the strong, sunlit backlight, neither exposure captured any detail in the window frame.
Certain picture elements — strong direct backlight, translucent materials, and thin objects like blinds or branches — are always going to prove problematic. The fancy and surreal tone-mapped stuff that you see on Flickr is often the result of pushing the process way past correction. If that is what you want to do, Qtpfsgui is the easiest way to go on a Linux system. The documentation recommends the Fattal algorithm for producing the most outlandish effects — those that reduce the overall image contrast the most, making the sky and the foreground alike almost flat.
You can even use Qtpfsgui to produce unnatural tone-mapped images from a single frame, although you are better off starting with multiple, bracketed exposures. But if you like experimenting with the weird look, try it even on normal, single-exposure shots.
Qtpfsgui does not provide any mechanism to align the images that it merges; any misalignment will result in ghostly artifacts likely to be exaggerated by tone-mapping. Since Qtpfsgui does not provide any image editing tools, it is best to shoot all input frames on a tripod, and to minimize camera shake with the longer exposures.
That way you can import RAW originals directly. You need to make sure you save the EXIF tags with the image, though. If it cannot find the exposure data, Qtpfsgui will prompt you to enter it manually for each frame — a hassle it is best to avoid. Considering how useful and interesting the task that Qtpfsgui performs is, it is almost a shame that it is a standalone tool and not integrated into other photo apps.
Integrating it into a workflow now means either processing and correcting the RAW files in a separate app first, then exporting them to TIFF for Qtpfsgui, or tone-mapping the RAW files in Qtpfsgui first, and touching up the output in another app second. But what a minor nit-pick that really is. Qtpfsgui enables Linux users to do some fancy stuff — both useful stuff like automating the correction of hard-to-fix images and wild and crazy stuff like generating those bizarre, artsy images that are such a craze on Flickr.
About Us. Sign in. Forgot your password? Get help. Password recovery. To do this, click each image in the editable images list and see if there is any haloing in that image. If you see it, adjust the image using the arrows in the Shift Values for Editable Image area of the dialog. Move the image until the haloing disappears or is minimized. Continue to do this for all the images in the Editable list. From the Preview Mode dropdown list you can choose from various preview modes which can help you identify alignment problems.
Later you can open this in the program to work on it and you will not have to realign and re-render it. Before you can actually use the image, you need to tone map it so select the Tonemap the HDR option to open the image ready for tone mapping.
To view one of the tone mapping options, select Fattal as the operator and click Apply. A small version of the image appears tone mapped to the specifications shown. Change the image size by selecting a different size from the Result Size options and click Apply to create a second version of the tonemapped image. Each time you click Apply you get another image so the screen can start filling up very quickly. You will find larger size images take more time to render so start with small versions until you find an Operator and settings that work for you then render larger versions as you fine tune your settings.
Here the larger size image is showing noise not apparent in the smaller image. Continue to experiment with options by choosing different settings — sometimes small differences in values can result in sizeable differences in the images and you can also use other Operators if desired.
Render the images you like at a good size and close any smaller versions or any images you do not like.
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