Showfoto Configuration


Showfoto tries to give you as much control over how it works as possible. There are many options that change the behavior of the application. To access these settings select SettingsConfigure Showfoto... from the menubar. The configuration dialog is separated by categories displayed in separated pages. You can change between these pages by clicking on the icons on the left-hand side of the dialog.

Tooltip Settings

This setup page covers all options of information appearing when the mouse hovers over a file icon in the Image Area. According to the checked options they will be shown or not.

See below an example of the information displayed in a tooltip over an icon with the relevant settings done in the configuration page.

Metadata Settings


Image files can have some metadata embedded into the image file format. These metadata can be stored in a number of standard formats as JPEG, TIFF, PNG, JPEG2000, PGF, and RAW files. Metadata can be read and written in the EXIF, IPTC, and XMP formats if they are present in the file.

Behavior Settings

Rotate Actions

Show images/thumbnails rotated according to orientation tag : this will use any orientation information that your camera has included in the EXIF information to automatically rotate your photographs so that they are the correct way up when displayed. It will not actually rotate the image file, only the display of the image on the screen. If you want to permanently rotate the image on file, you can click with the right mouse button on the thumbnail and select Auto-rotate/flip according to EXIF orientation. The image will then be rotated on disk and the tag will be reset to "normal". If your camera routinely gets this orientation information wrong you might like to switch this feature off.

Set orientation tag to normal after rotate/flip : the Auto Rotate option automatically corrects the orientation of images taken with digital cameras that have an orientation sensor. The camera adds an orientation tag to the image's EXIF metadata. Showfoto can read this tag to adjust the image accordingly. If you manually rotate an image, these metadata will be incorrect. This option will set the orientation tag to "Normal" after an adjustment, assuming that you rotated it to the correct orientation. Switch this off if you don't want Showfoto to make changes to the orientation tag, when you rotate or flip the image.

Metadata Filters

For each Metadata viewers available in metadata sidebar tab, you can customize which tab can be visible or not when you switch metadata tags list-view in filter mode. Exif, Makernotes, Iptc, and Xmp tags managed by Exiv2 shared library in background are listed in these filters list and the tags selection will be saved by Showfoto. To help you to choose the right tags to filter, a search engine is provided on the bottom of lists. For each tag, a helper description is provided. Three buttons permit to Clear current selection, Select All tags from the list, or only the Default list grouping the most common tags to use while photographs review.


Remember that from metadata sidebar tab, you can switch from one photo to another with the same active tags filter to quick compare embedded information from files.

Exif filter view

Makernotes filter view

Iptc filter view

Xmp filter view

Editor Settings

Editor Window Settings

By default the Image Editor will use a black background behind photographs when they are displayed. If you prefer a different background color you can choose one here. You can also turn off the ToolBar when the Image Editor is in full screen mode.

Over and underexposed areas of an image can be indicated by dark and light marker colors that can be defined here. In the editor this viewing mode can be switched on and off with F10 and F11 respectively. The thresholds for over- and under-exposure can be set by the adjustment bars "... percents". Check Indicate exposure as pure color if you want only pure black (RGB 0,0,0) indicated as under-exposure and only pure white (RGB 8 bit 255,255,255 respectively RGB 16 bit 65535, 65535, 65535) indicated as over-exposure.

Save Image Options

When changes are made to JPEG files and they are saved back to the hard disk the JPEG file must be re-encoded. Each time a JPEG file is encoded a decision must be made on the level of quality that is to be applied. Unfortunately the level of quality applied is not recorded in the image file. This means that the Image Editor cannot use the same quality ratio when saving an altered image as was used for the original image. You can change the default level of quality that the Image Editor will apply when it saves altered images by moving the JPEG quality slider (1: low quality / 100: high quality and no compression). At the time of writing, metadata is supported.

Chroma subsampling is the practice of encoding images by implementing more resolution for luminance information than for color information. Please read this Wikipedia article for a full explanation.

With PNG compression option, you can reduce PNG image files size. This operation does not reduce image quality because PNG uses a lossless algorithm. The only effect is that image data needs more time to compress/decompress. If you have a fast computer you can change this value to use a high compression factor (1: low compression / 9: high compression). At the time of writing, metadata is supported.

With Compress TIFF option, you can toggle to use Deflate compression algorithm with TIFF image files. This will reduce TIFF image files sizes. It has no image quality effect because Deflate is a lossless algorithm. At the time of writing, metadata is supported.

With the LossLess JPEG 2000 files option allows for lossless storage, or, if the lossy options is selected, even then the quality for comparative files size is much better than normal JPEG. At the time of writing, metadata is supported.

With the LossLess PGF files option allows for lossless storage, or, if the lossy options is selected, even then the quality for comparative files size is much better than normal JPEG-2000. At the time of writing, metadata is supported.

Image Versioning Settings

Non-Destructive Editing and Versioning gives you the freedom of editing your images, trying out whatever you want without worrying that you might regret later what you did. Showfoto takes care of the original and every important intermediate step if you want.

In the checkbox at the top you can enable or disable Non-Destructive Editing and Versioning.

In the first field you can choose the file format used for saving the intermediate steps and the final result. Remember that JPEG - like in the screenshot above - is a lossy format. So if you need to start over from an intermediate step it wouldn't be really non-destructive. If you can afford it in terms of space on the harddisk and loading/saving speed you better choose a lossless format like PNG or PCF for instance. Please click the information button on the right side for more detailed information.

In the next field you can decide whether the editor will save changes automatically on exit or should ask first.

In the third field you decide on which occasions you want the editor to save intermediate steps. Please click the information button on the right side for more detailed information.

In the last field you can adjust whether you want only the last version to be shown in the Image View (default, none of the boxes checked) or if you also want to see icons of the original version and/or intermediate steps.

RAW Decoding Settings

In the early versions of Showfoto the Image Editor was just a viewer for photographs, but it is rapidly developing into a very useful photo manipulation tool. This dialog allows you to control how the Image Editor will behave when opening RAW files.

Fast and simple, as 8 bit image

RAW files will be decoded to 8-bit color depth with a BT.709 gamma curve and a 99th-percentile white point. This mode is faster than 16-bit decoding. In 8-bit mode only the Auto Brightness setting will be taken into account (dcraw limitation).

Use the default settings, in 16 bit

If enabled, all RAW files will be decoded to 16-bit color depth using a linear gamma curve and according to the settings in the RAW Default Settings tab. To prevent dark image rendering in the editor, it is recommended to use Color Management in this mode.

Always open the Raw Import Tool to customize settings

With this option checked the Raw Import Tool will open at the Right Side Bar in the Image Editor so that you can set individual parameters for every image you open.

RAW Default Settings


A demosaicing algorithm is a digital image process used to interpolate a complete image from the partial raw data received from the color-filtered image sensor internal to many digital cameras in form of a matrix of colored pixels. Also known as CFA interpolation or color reconstruction.

Interpolate RGB as four colors

The default is to assume that all green pixels are the same. If even-row green pixels of the CCD sensor are more sensitive to ultraviolet light than odd-row this difference causes a mesh pattern in the output; using this option solves this problem with minimal loss of detail. To resume, this option blurs the image a little, but it eliminates false 2x2 mesh patterns with VNG quality method or mazes with AHD quality method.

Do not stretch or rotate pixels



TODO Showfoto and Dcraw offer us three alternatives: bi-linear, VNG interpolation, AHD interpolation. It seems that AHD interpolation (for Adaptive Homogeneity-Directed) is the best choice for quality according to some test that I have performed and the paper of the person that implemented it. VNG interpolation (Variable Number of Gradients) was the first algorithm used by Dcraw but suffers from color artifacts on the edge. Bilinear is interesting if you are looking for speed with a acceptable result.



Refine interpolation

This option is available only for DCB and VCD/AHD. TODO

White Balance


Four options are available here: Default D65, Camera, Automatic and Manual. Default D65 reflects normal daylight conditions. Camera uses the camera's custom white-balance settings if set. ??? Automatic The default is to use a fixed color balance based on a white card photographed in sunlight. ??? Manual will adjust colors according to the T(K) (color temperature in degrees Kelvin) and Green settings. TODO


This is the story of the three highlight options, courtesy of Nicolas Vilars:

Default is here to consider highlights (read: part of your images that are burned due to the inability of your camera to capture the highlights) as plain / solid white (solid white option). You can get some fancy results with the unclip option which will paint the highlights in various pinks. At last you can try to consider recovering some parts of the missing information from the highlights (reconstruct option).

This is possible because the blue pixels tends to saturate less quickly than the greens and the reds. Showfoto/dcraw will try to reconstruct the missing green and red colors from the remaining none saturated blue pixels. Of course here everything is a question of tradeoff between how much color or white you want.

If you select Reconstruct as the option, you will be given the choice to set a level. A value of 3 is a compromise and can/should be adapted on a per image basis.


A small warning here, for the few curious that have read the man pages of Dcraw, the author says that 5 is the compromise, 0 is solid white and 1 unclip. This is because in Showfoto 0 and 1 are the "solid white" and "unclip" options in the drop down menu (if you select these, the level slider will be grayed out). Therefore, the slider in Showfoto with the "reconstruct" option will let you choose between 0 to 7 (instead of 0 to 9 in Dcraw command line) where 3 is the compromise instead of 5 in "native" Dcraw command line tool.

Exposure Correction (E.V)


Correct false colors in highlights


Auto Brightness



Noise Reduction

TODO While demosaicing your image you can additionally ask for noise reduction (at a slight speed penalty). This option applies a noise reduction algorithm while the image still is in CIE Lab color space. Because the noise is only applied to the Luminosity layer (the "L" of the Lab), it should not blur your image as traditional noise reduction algorithms do in RGB mode. So, if you converted an image from RAW and it appears noisy, rather than applying a denoiser, go back and re-convert with this option enabled. The defaults are: Threshold = 100. Higher values will increase the smoothing, lower will decrease smoothing.

Enable chromatic aberration (CA) correction

If you know the CA of your lenses you can set the red and blue correction values here. This is certainly the optimal method for CA correction as it is done during RAW conversion.

Color Management Settings

Showfoto is color-management enabled. RAW files - as they come - are not color managed at all. Your camera provides the data it has captured in a raw format and will let you manage all the processing. Every camera has its specifics as to how it captures color information, therefore you will need to apply a specific profile to the images you want to process. Please refer to the section ICC color profile management for more details an explanations.

Basically, a profile "maps" the color information and gives information on how one should render them. It gives also information to LCMS and Showfoto on how to translate the color information from one color space to an other in order to keep the colors as accurate as possible across all rendering media.

Behavior Ask when opening an image in image editor / Launch Color Management tool with RAW files

Color Profiles Directory : set this to the folder where you store all your profiles e.g. "/usr/share/color/icc" or "/home/user/.color/icc". Showfoto will scan this folder when starting up.

ICC Profiles Settings : here you are given the ability to provide "default" choices for your profiles. Everything is adaptable later-on at the opening of a RAW file.

  • The Use color managed view is an alternative to using Xcalib or Argyll. Only your image will be color managed, not your entire screen!

  • You have to provide a workspace profile (linear profiles such as sRGB, ECI-RGB, LStar-RGB, Adobe-RGB or CIE-RGB). If you want to print your images, you may want to opt for Adobe RGB, if it is only for web publishing, sRGB is better (Adobe RGB will be displayed slightly dull in non color managed enabled software such as browsers). However you may change this later of course (by attributing another profile), therefore Adobe RGB can be a good choice for storing and image handling as you can always change it to sRGB before releasing an image for your blog. Note: Do not use non-linear profiles as they will change the color-balance.

  • The input profile should match the camera maker and model you are using. 'Not all profiles are created equal', there are some that have no tone mapping/gamma correction included (Canon). As of now, dcraw does not correct gamma for 16 bit depth conversion, which means that you have to do the tone mapping yourself.

  • There are some other options such as the soft proof profile which enables you to emulate, granted that you have a profile for it, how your image will render for a particular device. It is useful before printing for instance because your printer has a smaller gamut than your camera and some colors might look saturated. You may want to fix this manually instead of relying on the "blind" algorithm of your printer.

For most cameras it is pretty obvious what color profile they propose for the type at hand, not so for the Canon's. Here is a table of camera/profiles matches, it is non-authoritative of course:

CameraProfile series
Canon 1D mark II6051
Canon 1D mark II6111
Canon 1Ds6021
Canon 1Ds mark II6081
Canon 5D6091
Canon 10D6031
Canon 20D6061
Canon 30D6112
Canon 40D6101
Canon 300D6031
Canon 350D6111 or 6071
Canon 400D6131

The Canon profile extension betray the target style: F for Faithful Style, L for Landscape Style, N for Neutral Style, P for Portrait Style, S for Standard Style.

Here you find a typical RAW workflow scenario.

Slide-Show Settings

The slide show setup should be easy to understand. The upper slider adjusts the time between image transitions; usually a time of 4-5 seconds is good. The other check boxes enable/disable the metadata to be shown on the bottom of the slide show images during display.

Miscellaneous Settings

General Settings

With the Images Sort Order setting, you can select whether newly-loaded images are sorted by their date, name, or size on disk.

With the Reverse ordering setting, newly-loaded images will be sorted in descending order.

With the Show image Format setting, you can show image format over image thumbbar thumbnail.

With the Show Geolocation Indicator setting, you can show over image thumbbar thumbnail an indication if image has geolocation information.

Application Behavior Settings

With the Scroll current item to center of thumbbar setting, you can force thumbbar to center current selected item with mouse pointer on the center of visible area.

With the Show splash screen at startup setting, you can switch off the display of the splash screen when application loads. This may speed up the start time slightly.

With the Sidebar tab title setting, you can set how sidebars on the sides will show the tab titles. Use Only For Active Tab option only if you use a small screen resolution as with a laptop computer. Else For All Tabs will be a best choice to discover quickly all internal features of Showfoto.

With the Widget style setting, you can choose the default application window decoration and looks. Fusion style is the best choice under all desktop.

With the Icon theme setting, you can choose the default application icon theme. Theme availability depends of desktop used to run Showfoto.

The Theme Setup

Color schemes are supplied like themes to personalize Showfoto main interface for you pleasure. To access these settings select SettingsThemes from the menubar and select your preferred theme to use.