Fotoxx     22.50

Fotoxx is a free open source Linux program for photo/image editing and collection management. The goal is to meet the needs of serious photographers while remaining fast and easy to use.

Click the image above to see a full-size image.

Short Overview
Navigate a large image collection using a thumbnail browser, click on an image to view or edit. A rich set of edit and retouch functions is available. Import RAW files and edit with deep color. Save revised images as JPEG, PNG (8/16 bits/color), or TIFF (8/16). Select an object or area within an image (freehand draw, follow edges, flood matching tones...), apply edit functions, copy and paste, resize, blend, warp, etc. without using layers. Edit functions have fast feedback using the full image or selected zoom-in area. Edit image metadata (tags, geotags, dates, ratings, captions...). Search images using any combination of metadata and file and folder names or partial names. Click a marker on a scalable world map to view all photos from that location. Batch functions are available to rename, add/revise metadata, copy/move, resize, convert format. Fotoxx uses your image files wherever they are and maintains a separate index for fast searching. Fotoxx is standards compliant and can be used with other photo programs (no lock-in). Fotoxx is easy to use but unconventional, so read the user guide (at least the first few pages) before jumping in. Fotoxx has deep functionality. Do not expect to master it in a few minutes.

A more detailed description and list of capabilities can be found at the end of this document:
Fotoxx Long Overview
Fotoxx Demo (YouTube video)
A basic overview of Fotoxx.

Fotoxx Sample Images (YouTube video)
A collection of before/after images edited with Fotoxx.
The latest release can be obtained here: downloads.
Packages for many Linux flavors can be found HERE and HERE.

Fotoxx works best on a strong computer (4+ CPU cores, 8+ GB memory). 64-bit Linux is required. Lesser computers may be slow or may fail to edit large images. The monitor should be at least HD (1920x1080) and have accurate color.
Performance and Limitations
Most image edit functions respond within 1 second for images up to 20 megapixels on a strong computer. 200 megapixel images can be edited on a computer with 16 GB RAM. Composite functions (panorama, HDR ...) may need a minute or more when combining many large images. Image search time is generally below 1 second for collections up to 300K images.

Usage Examples
Click on the small images to see a full-size image.

View a large collection of image files using a thumbnail gallery. Click on a thumbnail to view or edit a full-size image. Move around within gallery pages and navigate to other pages. A gallery may be a folder of image files, the output of an image search, or an album (ordered set of images). The thumbnails can be large or small and can be zoomed out to any scale with the mouse wheel. Images can have geotags (via camera GPS or manually added). A scalable world map shows image location markers. Click on a marker to get a gallery of images.

RAW file import
The first image is the JPEG produced by the camera. The 2nd image is the RAW file from the camera, converted to TIFF-16. The 3rd image is the edited TIFF file saved as a JPEG file. The dark areas were lightened and color was slightly increased.

RAW files can be directly opened and edited, or you can use a batch function to select and convert many RAW files at once. The speed is 2-4 seconds per file on a strong PC. The converted files can be JPEG, TIFF (8 or 16 bits per RGB color), or PNG (8 or 16 bits). All internal editing is done with 24 bits per color.

Search Images
Add tags (keywords), geotags, titles, captions, dates, and ratings to images. Search images using these criteria as well as image file and folder names. Partial matching also works. Matching images are shown in a thumbnail gallery. Click a thumbnail to view or edit, or step through sequentially. Search speed is nearly instantaneous.

Tags, etc. are stored inside the images using EXIF and IPTC standards. They can be shared with other standards-compliant photo programs.

Search Metadata
Find images with any desired metadata, show thumbnail images with metadata text. Click a thumbnail to view full-size. There are also functions to view the key metadata for an image, view all available metadata, or edit any metadata.

The search speed is almost instantaneous for 'main' (indexed) metadata. The speed is slower (a few thousand files per minute) for metadata that is not indexed and must be read from the image files.

You can optionally add metadata items to the index for fast searching.

Cameras with GPS receivers can add geotags (location name and earth coordinates) to images automatically. Fotoxx also has a function to find the earth coordinates for a given location (city, park, monument ...) and add geotags to a bunch of images at once. If many photos made in one location are located together in your collection, you can quickly process all of them. If this work has been done, you can use the following geotag functions to find and display images from a given location as a gallery of clickable thumbnails.

Search Images Using Geotags

List image locations: group by country, country/location, or country/location/date. Click on a list entry to see all the images in that group as a gallery of thumbnails. The example here shows 28 photos made in Jan. 2012 at Achensee, Austria. If listing by dates, you can consolidate dates that are separated by less than a given number of days.

Search Images by Clicking on a Map
Click on a map location to instantly see all the photos made in or around that location. Location names pop up as you move the mouse over the map. In this case, "Leipzig" was clicked to retrieve 25 photos of Leipzig.
Search Images Using a Calendar

The calendar report shows image counts by year and month. Click on any month to get an instant gallery of images for that month.

Edit Selected Object or Area

Little Mermaid was back-lighted. The fix was to select her and flatten (spread out) her brightness distribution. Areas are selected using the mouse: freehand draw, follow edges, or spread into matching tones from the mouse position outwards. Edge effects can be automatically blended out.
Copy and Paste Selected Areas

Drag into position, resize,
edit colors, etc.

Select Complex Edges
Hair and other irregular shapes can be accurately selected. Drag over the area with the mouse, clicking as needed on colors to be selected or suppressed. This can be tedious if the background contrast is weak. This example is about a 10 minute project for an experienced user. Novices will need more time to get the feel of this tool.

Flatten Brightness Distribution
This tool is an easy way to improve detail in areas that lack contrast. Uses a single sliding control with live feedback. Sometimes works miracles and sometimes not very effective. Good for fog/haze removal.

Other tools to auto-improve images:
Local Contrast: bring out detail in low contrast areas
Gradients: increase low brightness gradients only

Use within selected areas for local optimizations.
Global and Zonal Retinex

This tool can be used to restore the full color range for a badly faded photo or one with an extreme color caste. It can also be used to add flair to any image. The original and modified images can be blended in any ratio.

View 360°Panorama Image
This tool is used to view a 360°panorama image. Use the mouse to rotate the viewpoint through the full 360°. The view window is 90°(right image) and can be zoomed-in for a larger/narrower view.
Sharpen Image

Comparison of different sharpening methods on a blurred image.

The 'gradient' method increases sharpness about as well as the classic 'unsharp mask' method, but with less "halo" effect around high-contrast edges. 'Kuwahara' produces excellent sharpness but small details are lost.

Noise Suppression

Reduce noise in photos made under low-light conditions.

Which method works best depends on
image and noise characteristics.

Measure image noise

Noise can be measured and noise suppression
can be quantitatively evaluated.

Watermark an Image

Add embedded text with various styles.

Revise Brightness by Editing a Curve

Edit a brightness curve while watching the live output image.

Defog London

Remove fog and haze with flatten and gradients.


Compensate for radial brightness loss (vignetting), or highlight some part of the image. Response curve can be customized, saved and reused. Use the mouse to set the center for the response curve. Image can be brightened or darkened, or a color-caste can be added or removed.

Smart Erase
The power lines and poles were erased. Select an object to erase using the mouse like a paintbrush. Click to erase. Neighboring pixels replace the erased area. This usually works well for small or narrow areas, or even larger areas when surrounded with fairly uniform background, like sky or grass. Selecting long thin objects like power lines is done by clicking positions along the length.

Remove Dust

Remove the dust spots from images made from dusty scanned slides or old photo prints.
Remove Chromatic Aberration (color fringes)
Click to enlarge and view carefully. The left image is a photo taken from inside a church (a small cutout of a large image). It has color fringes on the dark to bright transitions, and these were mostly eliminated in the edited version on the right. Slider controls change the scale of individual RGB color planes, and you simply adjust them to minimize the color bands. It works for the usual sort of chromatic aberration which increases radially from the center.

Increase contrast where it is weak without changing overall contrast.
Watch the image change as you move a curve or slider.

This one was taken to extremes, giving the impression of an illustration.

Tools for Brightness and Contrast

5 methods to change brightness and contrast
Remove Motion Blur
Compensate camera or subject motion.
The camera was panned during the exposure to create motion blur. This was mostly removed using the Richardson-Lucy method. Drag the mouse to indicate the blur angle and input an estimated blur span. Vary inputs to optimize result.
For subject motion, use Select Area to isolate the blurred subject from the sharp background.
HDR - High Dynamic Range Image
The lower image is a composite of the upper ones. Brighter areas were taken mostly from the darker image, and darker areas from the brighter image. Optionally use editable curves to adjust the contribution of each image for each brightness level.

Gradients tool was used after the images were combined.

The camera was hand-held. The automatic alignment works well unless the camera is shifted significantly between shots. The people moved between the photos, so ghosting can be seen.

HDR made from photos having significant camera movement and rotation.
Minor changes in image scale are compensated.
HDF - High Depth of Field
Combine multiple photos of the same subject, each having a different focus distance. The combined image has a depth of field spanning all the input images. This function is very sensitive to changes in camera position or aiming point - these cause parallax errors and changes in image scale that cannot be fixed with simple translation and rotation. The software compensates for small errors in scale. If you are careful not to move the camera too much, you can get good results. All photos here were hand-held.
This HDF required several minutes of manual work to choose which input image to use for each area in the output image. This is done by choosing an image and "painting" with the mouse. This can take time if there are lots of adjacent near and far areas which must be painted separately using different underlying images.

This one was easy because there are no adjacent near and far areas.

Stack - Noise Suppression
9 photos were made at ISO 1600 in a darkened room with a hand-held camera. My strong computer needed nearly a minute to align and combine them into one low-noise image. This is part of the 20-megapixel image, shown at full size.

Stack - Paint
The two images were taken a few seconds apart, during which time the cyclist (left image) moved out and the red car (right image, left side) moved in. The images were combined, and the car and cyclist were removed by choosing one image or the other and "painting" with the mouse.
Four photos made in quick succession.
Stack - Paint can be used to make transient objects disappear or make them appear multiple times.

Combine up to six images to make wide-angle images. Rough alignment is done with the mouse and fine alignment is automatic. All photos here were hand-held.

Indoor scene (house pet was pasted in).
Brightness and color matching was automatic.

3 images with poor camera handling. The final image was straightened and retouched for brightness and color.

6 photo panorama spanning almost 180 degrees.

A vertical panorama. Brightness and color matching was automatic.


Photo montage. Add images and text to a background layout of arbitrary size. Images and text can be moved around using the mouse, resized, rotated, and made party or wholly transparent. Transparency can be painted gradually or fully. Text can have any font, size, and angle. Background, outline and shadow can be added to text, with adjustable color and transparency for all of these.

Magnify Image

Move around over an image with a simulated magnifying glass.
Diameter and magnification are adjustable.


Sometimes panorama images must be straightened.
Adjust while watching a live output image.

Fix Perspective

Fix images photographed from an angle, e.g. paintings, buildings, etc.
Select the 4 corners and transform into a rectangle.

Fix Barrel Distortion

RAW files can have lens distortion if the raw converter has no correction data for the camera and lens combination. This can be easily fixed using only eyeball judgement.

Flatten photo of a curved surface
Flatten the page edges and stretch the squeezed text where the page curves down at the center binding. Mark the page top and bottom edges at several points using the mouse. The rest is automatic. Use for any curved image, e.g. a poster on a round column.

Pixel Edit

Use for retouching. Pick a color from the image or from a palette. Variable brush size and transparency allow gradual change without edge effects.

Warp Image, 4 variations

Pull the image with the mouse.
The image behaves like sheet rubber.

Unwarp Close-up Photo (selfie)
Close-up portraits exhibit a "balloon face" distortion.
There is a special function just for this problem.

Improve Botticelli

Straighten her eyes and smooth her skin.

Make Mosaic Image

Make any image into a mosaic with tiles created from your images. Click on a tile to get a larger popup image which you can resize and drag. This requires that you have thousands of images in your collection, with an adequate range of available colors.

Click on image to view full size.
Make a Table of Images
Images can be mixed sizes. They are rearranged and resized as needed to make all the columns as even as possible.

You can click on any image to get a larger popup image which can be zoomed to any size, and disappears with another click.
Add Texture to an Image

Combine texture with gradients and embossing to get interesting effects.

Add Background Pattern
A background pattern can be added to an image or selected areas. The pattern is a small image that is repeated to cover a larger area. If the pattern repeats, dimensions are found automatically to make the pattern seamless (left example). The pattern can be a photo of a texture, as in the right sample. Pattern scale and opacity are adjustable.

Write Text

Write text on images. Select font, colors, transparencies, shadow, angle. Watermarks are made by writing faint text and embossing.

Lines, arrows, boxes, and circles/ovals can also be added.

Fix a Lousy Photo

The upper photo had multiple retouches to produce the one below. The functions used were trim/rotate, flatten brightness distribution, increase contrast, increase color saturation, and gradients. These were applied in different areas of the image.

The photo was back-lighted and the Fall colors came out faded. The following steps were made in sequence: select the sky, invert the selection (everything but the sky), increase overall brightness with an upward slope for more contrast, select the foreground vegetation areas, add more contrast, add color saturation, add slight gradients.
Art Effects
Convert a photo into a simulated drawing, painting, embossing, cartoon. These take a few seconds to a few minutes, depending on how long you want to play with the controls to optimize the result.







Your Veteran Coder


Fotoxx is a free Linux program for editing photos or other images and managing a large collection. Fotoxx has powerful editing tools to correct and enhance photos. Fotoxx can instantly find desired images within a huge collection, based on folder and file names or embedded metadata such as dates, tags/keywords, titles, comments, ratings, location, camera data - any metadata.

Image folders can be viewed as a scrolling gallery of thumbnail images. Navigation of folders and subfolders is simple and fast. Click on a thumbnail for a full window view of the image. The image can be zoomed, panned and scrolled using the mouse. Gallery thumbnails can vary from small to huge. Popup windows can be used to view or compare multiple images at any scale. Thumbnail galleries are also used to display image search results and albums. Albums are selected images arranged in a desired order. Fotoxx has many editing tools that go beyond the basics. Images with severe problems (underexposed, false colors, blurred, uneven lighting, fog/haze) can be brought back to life. Details lost in shadows or haze can be brought out. Images with distorted perspective (esp. wide-angle views) can be corrected.

Fotoxx is standards compliant. Nothing done by Fotoxx makes your images less usable with other applications. Fotoxx uses your image files wherever they are: they are not moved or duplicated. Fotoxx does create an index for fast image searching, and thumbnail images for fast gallery displays. These add typically 2% to overall storage requirements. There is no database to manage - the index manages itself. 

Fotoxx can import RAW images and perform all processing in deep color (24 bits per color used internally). Edited images can be saved as JPEG, TIFF (8/16 bits/color), or PNG (8/16 bits). Convert single RAW files (click thumbnail) or selected batches (click thumbnails from gallery pages).

Image edit functions are interactive with rapid visual feedback, using the full image or a chosen zoom-in area. Undo and Redo can be applied serially to all the edits of an image. Intermediate and final results can be saved as new files or as versions of the input file (e.g. filename.v02.jpg).

Objects or areas within an image can be selected and edited separately from the background. Areas can be selected using several methods: drag the mouse to select and flood into matching tones, follow feature edges, or outline an area freehand. Complex feature edges, such as hair or foliage, can be accurately selected. Selected areas can be copied and pasted into the same or other images, resized, rotated, brightened, etc. Layers are not used. Each edit stage can be saved separately as a file 'version'. These can be re-used to make new versions. Prior versions or other image sources can be "mouse painted" onto areas within new versions or images - paint from any source to any destination, with simultaneous rescale if wanted.

Batch functions are available to copy, move, rename, resize, upright, convert format, convert RAW files, and add or revise metadata.

Several tools are available to change size and shape: crop, resize (rescale), rotate, fix perspective, curve/warp the whole image or selected areas within the image. There is a special tool to 'flatten' photos of curved surfaces, e.g. a page from a thick book or a poster on a round column.

Text can be added to an image. Any font and size can be used, any color, any angle. The text can have variable transparency, an outline, a shadow, or an embossed effect - good for a signature or copyright. Other basic markups are available: lines, arrows, box, oval/circle.

Dust spots from old slides or photos can be removed, roadside trash or power lines can be erased. Panoramas can be made by stitching photos together seamlessly, automatically matching brightness and color. Photos with a range of exposure values can be combined into an HDR image with adjustable contributions. Photos with varying focus depths can be combined into an image that is sharp over the combined range. Photos of one scene taken at different moments can be combined to remove passing autos or tourists. Multiple photos made under low light conditions can be combined to reduce noise. Images and text can be combined into a mashup, using the mouse to position and resize the components and adjust overlaps and transparencies.

Fotoxx has a batch scripting tool to speed the processing of multiple images requiring the same edits: record the edits made to a base image and then apply these edits automatically to any number of selected images.

Many special effects ('filters') are available to convert a photo into a line drawing, sketch, painting, embossing, cartoon, dithered image, mosaic, or abstract patterns. Background patterns and textures can be added.

Images can be rapidly searched using file and folder names or partial names, dates, assigned tags, ratings, locations, and any other metadata stored in the image. Some data is automatic from the camera (date, location, exposure data), and other data can be manually entered (tags, captions ...). Batch tools are available to load metadata into many images at once. Search criteria can be used in combination; e.g. find Chicago photos for years 2002-2005 containing tags 'Barbara' or 'Barbie'.

Locations (from a camera GPS sensor or entered manually) can also be searched. You can view a map of any region in the world, at any scale, using an internet map service. Images having location data show as markers on these maps. Click a marker to get a gallery of the corresponding images. Local map files of the world, each continent, and some countries are also available, and you can add your own maps at any scale. Local maps have no dependency on the internet. You can jump from a given photo to its position on a world map, where you can find other photos from the same or nearby positions.

Albums can be made using selected images from your collection. The files are not duplicated. Select images by clicking gallery thumbnails. Arrange the images with drag and drop. Albums can be made into slide shows. Choose animated transitions between images, pan and zoom effects, and places to auto-pause for narration.

Fotoxx includes a comprehensive user manual that also serves as interactive help: press F1 while using any function in Fotoxx. You should take the time to read the overview pages. The function details can be viewed as needed.

   Displays, reports, and edit functions are accessed via menu buttons and popup menus.
   Interactive dialogs are used to control each function. These may have buttons, text
   or numeric inputs, sliders, and pick-lists. Some dialogs use editable curves that
   can be manipulated with the mouse or equivalent touchpad actions.

   File View: The main window shows a single image file, which can be zoomed and
      panned with the mouse. Edit functions modify this image as directed by dialog
      inputs or mouse actions on the image.
   Gallery View: A thumbnail browser/navigator showing an array of thumbnails for a
      folder of image files, or for an album or report of image files. Each thumbnail
      has text for the file name, and more text depending on context. The gallery can
      be scrolled using the scroll bars or mouse wheel. Thumbnail size can vary from
      small to huge. Clicking a thumbnail will select the image file for viewing or
      editing, or for inclusion in a function working on multiple image files.
   Map View: An interactive internet map is scalable from street to global level.
      Zoom and pan using the mouse. Image files having geocoordinates in metadata
      show as markers on this map. Clicking a marker produces a thumbnail gallery of
      the underlying image files. Custom map files may also be used the same way.
   NEW SESSION - start new parallel Fotoxx session in a separate window
   OPEN IMAGE FILE - navigate folders, select an image file for view or edit
   SOURCE FOLDER - open corresponding Gallery View for current File View image
   CYCLE 2 - cycle through the two most recently seen image files (A/B compare)
   CYCLE 3 - cycle through the three most recently seen image files (A/B/C compare)
   VIEW 360° PANO - view a 360° panorama image with rotating viewpoint (mouse pan)
   RENAME - rename an image file
   DELETE/TRASH - delete or trash an image file
   COPY/MOVE - copy or move an image file to another folder, desktop, or clipboard
   PERMISSIONS - view and set access permissions for an image file
   REMOVE ALPHA - apply alpha level to RGB levels and remove alpha channel
   SHOW ON MAP - change to Map View, with marker for current image file at center
   SET WALLPAPER - set the desktop wallpaper from the current image file
   PRINT - print an image file (set scale, orientation, paper type, quality)
   PRINT CALIBRATED - print an image file using printer color calibration data
   QUIT - exit from Fotoxx

   THUMB VIEW - Gallery View with thumbnails and file names and dates
   META VIEW - Gallery View with thumbnail and basic metadata used by Fotoxx
   RECENT - open Gallery View of most recently seen images
   NEWEST - open Gallery View of newest images in the collection
   GOTO FIRST or LAST - jump to gallery start or end
   SORT GALLERY - sort by file name, file/photo date, file/pixel size
   ALL FOLDERS - folder hierarchy, expand/contract each level, click for gallery
   SELECT FILES - select files for an album, or input for batch/script function
   RENAME FOLDER - rename the current folder (file gallery)
   ADD SUBFOLDER - add a new subfolder to the current image folder
   BOOKMARKS - view list of bookmarks, add/remove bookmark, go to bookmark
   MANAGE ALBUMS - create and arrange an arbitrary collection of image files
   UPDATE ALBUMS - update album files for updated image files (new versions)
   ALBUM MASS UPDATE - utilities for mass addition or update of album files
   GALLERY TO ALBUM - make an album from the current gallery (search result)
   SLIDE SHOW - create a slide show with animated transitions and image pan/zoom

   NET MAP - view an interactive scalable internet map, pan/zoom with mouse.
      Maps have markers for images with location metadata. Click for gallery.
   NET MAP LOCS - define or go to a named map location (position and scale)
   FILE MAP - view local file map with similar functionality.
   CHOOSE MAP - choose from available maps (World, USA, France, NYC, etc.)
      Custom maps can be added and work the same way.
   MARKERS - show map markers for all images or only the current gallery

CUSTOM MENU - open a custom user menu for frequently used functions
ZOOM BUTTON - left/right click to increase/decrease image or thumbnail size
PREV/NEXT BUTTON - left/right click to view previous/next image in current gallery
FILE SAVE - save an image file (replace, new version, new file name/location)

   VIEW META - list main image metadata in a popup window
   VIEW ALL META - list all image metadata in a scrolling popup window
   EDIT META - edit commonly used metadata in a popup dialog
   EDIT ANY META - edit any metadata item (add, delete, revise)
   DELETE META - delete specified metadata or all metadata
   COPY META - copy metadata from one image file to another
   MANAGE TAGS - manage user-defined tags (keywords for searching)
   CAPTIONS - show/toggle file name, title, description in top left image corner
   PLACES/DATES - list all image locations and date groups, click for gallery
   TIMELINE - calendar layout of image counts by year and month, click for gallery
   SEARCH IMAGES - search images using folder/file names or any metadata
      (dates, tags, locations, ratings, words in text metadata, exposure data ...)
   AUTOSEARCH - shell scripts can use the Search function to select image files

   SELECT AREA - select an image feature or area for separate editing.
      methods: outline by hand, follow feature edges, select by color tone,
      'flood' selection into color tones matching mouse position.
   COPY/COMPLEX - select and copy area with complex edges (e.g. hair)
   FIND AREA GAP - find the gap in a hand-drawn area outline
   EDGE BLEND - mouse-blend edges of edits made within a selected area.
      Also called 'feathering' the edges over a desired pixel span.
   SHOW/HIDE AREA - show or hide area outlines
   ENABLE/DISABLE AREA - enable or disable an area for editing
   INVERT AREA - invert an area (reverse the outside/inside pixels)
   CLEAR AREA - remove an area
   COPY/PASTE AREA - copy an area and insert somewhere else later
   LOAD/SAVE AREA - load an area from a file or save an area to a file

   Sequential undo or redo edits to current image.
   Go back to any prior edit of the current image.

   ROTATE - rotate or level an image, or upright 90 deg. rotated image
   CROP - crop (trim) image margins, optionally use fixed aspect ratio
   RETOUCH - edit brightness, contrast, color temperature, saturation, and
             white balance. Optional edit curves for brightness/RGB levels.
   RESIZE - change the image pixel dimensions, optional fixed aspect ratio.
   UPRIGHT - upright a rotated image (usually automatic, or choose ±90°)
   MIRROR - mirror (or flip) an image horizontally or vertically
   MARKUP - draw on image: text, line/arrow, box, circle, oval.
            set font, shadows, size, angle, position (via mouse).
   COLOR MODE - convert to black & white, negative/positive, sepia
   PAINT IMAGE - mouse-paint with a color, brush size, and opacity
   PAINT EDITS - mouse-paint an edit function locally and gradually
                 (most edit functions can be painted this way)
   PAINT TRANSP - paint areas with (gradual) transparency using the mouse
   COPY IN IMAGE - copy pixels within an image using the mouse
   COPY FROM IMAGE - copy pixels from another image using the mouse
                     (conversion scale can also be varied)
   COPY PRIOR EDIT - copy areas from prior edits of the same image, using mouse
   PLUGINS - use another image editor (e.g. Gimp) as a Fotoxx edit function

   SHARPEN - sharpen a blurred image, multiple methods including Richardson-Lucy
   BLUR - blur an image or image area, multiple methods including paint blur
   DENOISE - reduce image noise, multiple methods
   DEFOG - add or remove fog/haze from an image or selected area
   RED EYES - remove red eyes from flash photos (usually one click)
   SMART ERASE - remove power lines, trash, signs, other small image spoilers
   REMOVE HALO - remove halos left by sharpen and other edit functions
   ADJUST RGB - adjust image colors using RGB/CMY scales
   ADJUST HSL - select and change colors using HSL scales
   COLOR PROFILE - convert color profile (e.g. sRGB <--> Adobe RGB)
   VIGNETTE - change brightness or color radially around a chosen center
   REMOVE DUST - remove dust spots on images scanned from old photos
   CHROMATIC 1 - fix chromatic aberration - color fringes increasing from center
   CHROMATIC 2 - fix chromatic aberration - color bands along bright/dark edges

   VOODOO-1 and VOODOO-2 - fast 1-click enhancement that may work well enough
   EDIT DIST - shift brightness distribution to rebalance dark and bright areas
   FLATTEN DIST - flatten distribution to improve detail in low-contrast areas
   LOCAL CONTRAST - add contrast adapted to brightness of local area
   GRADIENTS - increase brightness gradients where weakest
   GLOBAL RETINEX - rescale RGB values to remove color cast and fog/haze
   LOCAL RETINEX - rescale RGB values to remove color cast and fog/haze
   SATURATION - adjust color saturation, optionally based on brightness
   SOFT FOCUS - apply classic "soft focus" effect to an image (portraits)
   MATCH COLORS - match the colors in one image to those in another image
   BRITE RAMP - add a brightness/color ramp across an image or area

   SKETCH - convert an image into a simulated pencil sketch
   CARTOON - convert an image into a cartoon-like drawing
   DRAWING - convert an image into a color line drawing
   EMBOSS - convert an image into a simulated embossing (3D relief effect)
   TILES - convert an image into simulated square tiles with relief
   PAINTING - convert an image into a simulated painting
   TEXTURE - add texture to an image or selected area
   PATTERN - add a pattern to an image or selected area (e.g. canvas)
   DITHER - different ways to pixelize or posterize an image
   MOSAIC - convert an image into a mosaic using tiles made from all images
   ADD NOISE - add random noise to an image (mask banding, jpeg artifacts)
   COLOR DEPTH - reduce RGB bit depth or number of colors (posterize)
   SHIFT COLORS - gradually shift RGB colors to GBR or BRG
   ALIEN COLORS - add random strange colors to an image
   COPY/PASTE COLORS - copy/paste an RGB color plane across images
   CUSTOM KERNEL - edit and apply a custom convolution kernel to an image

   UNBEND - straighten warped image, esp. panorama or fisheye  July
   PERSPECTIVE - straighten an object photographed from the side or below
   WARP AREA - warp a selected image area by pulling with the mouse
   WARP CURVED - warp entire image or area using the mouse - curvy warp
   WARP LINEAR - warp image by pulling with the mouse - straight lines preserved
   WARP AFFINE - warp image by pulling with the mouse - parallel lines preserved
   AREA RESCALE - rescale an image down, leaving selected area at full scale
   UNWARP CLOSEUP - remove distortions of a close-up face photo (e.g. big nose)
   MAKE WAVES - warp an image with a wave pattern, vary length and amplitude
   TWIST - twist an image around a chosen center point
   SPHERE - curve an image into a spheroid shape (picture on a ball)
   STRETCH - add/remove barrel/pincushion distortion (RAW with uncorrected lens)
   INSIDE-OUT - invert the center-edge distance of each pixel
   TINY PLANET - wrap a panorama image around a circle
   ESCHER SPIRAL - transform an image into an endless inward spiral
   FLATTEN PHOTO - flatten photo of a curved image (e.g. thick book page)

   HDR - combine photos with varying ISO for an extended brightness range
   HDF - combine photos with varying focus depth for extended depth of field
   STACK/PAINT - combine photos to remove transient cars, tourists, etc
   STACK/NOISE - combine high ISO photos to reduce noise by averaging
   STACK/LAYER - combine images, select/paint which image to show in each area
   STACK/SPLIT - show two images overlapped with a movable boundary line
   IMAGE DIFFS - subtract two images (with offset) for artistic effect
   PANORAMA - stitch together a series of photos horizontally or vertically
   MASHUP - arrange multiple images and formatted text in an arbitrary layout
   IMAGE TABLE - join many images into a tablular format with margins.
     Images can be clicked to pop-out larger zoomable images.

   BATCH CONVERT - copy, move, resize, rename, convert format, add text ...
   BATCH COPY/MOVE - copy/move selected files to a new folder
   BATCH UPRIGHT - scan for rotated images and upright them
   BATCH DELETE/TRASH - delete or trash selected images
   BATCH RAW - convert RAW files to JPEG/PNG/TIFF, 8 or 16 bit color
   BURN DVD/BRD - create a DVD or BlueRay disc with selected image files
   EXPORT FILES - export selected files to a folder (e.g. for web upload)
   CONVERT ADOBE - convert Adobe files (.pdf .ps .eps) to jpeg, one per page
   BATCH TAGS - add or remove tags for selected images
   BATCH RENAME TAGS - rename tags for selected or all images
   BATCH PHOTO DATE - change photo dates or times, or shift time zone
   BATCH CHANGE META - add or revise metadata for selected or all images
   BATCH REPORT META - report metadata for selected or all images
   BATCH MOVE META - move metadata between keywords - fix irregular usage
      (e.g. 'caption' and 'title' - compensate metadata standards chaos)
   BATCH GEOTAGS - add or revise geotags for selected or all images
      (e.g. change 'München' to 'Munich' wherever found)
   EDIT SCRIPT - record a series of image edits in a script file
   RUN SCRIPT - execute script on current file (a custom edit function)
   BATCH SCRIPT - execute script on selected image files

   INDEX FILES - 1-time job to find and index all image files
   QUICK INDEX - quick incremental index with no user interaction
   PREFERENCES - dialog for user preferences and settings
   KB SHORTCUTS - show and revise keyboard shortcuts for menu functions
   RGB DISTRIBUTION - brightness distribution graph for the current image file
   MAGNIFY IMAGE - mouse is a magnifying glass over image, variable size and power
   FIND DUPLICATES - find duplicate images in a folder or entire image collection
   SHOW RGB - show RGB values at mouse position or for selected points
      (can be used to show edit function changes at the pixel level in real time)
   POPUP TEXT - show popup window with characters/texts to insert into edit widgets
      (default list: Ä Ë Ö Ü ä ë ö ü ß € ° ® ± µ ÷ ⁕ ‣ ▪ ➤ ᴧ ← ↑ → ↓ ↔ ↕ )
   CALIBRATE PRINTER - calibrate printer color - compensate printer color shifts.
      (improvement somewhere between good and poor, depending on printer and paper)
   GRID SETTINGS - show or remove grid lines, set line count or spacing
   LINE COLOR - set color for select area outlines and a few other cases
   DARK/BRIGHT PIXELS - tool to highlight possible clipping at 0 and 255
   MONITOR COLOR - tool to adjust monitor brightness and contrast
   MONITOR GAMMA - tool to adjust monitor gamma (requires xgamma app)
   SHOW RESOURCES - show CPU time and current memory usage in a popup window
   APPIMAGE FILES - export the files included in the Appimage container
   APPIMAGE UNINSTALL - uninstall the Fotoxx appimage package

HELP MENU - user guide, tutorial video, change log, privacy policy, about Fotoxx

      A comprehensive user guide is available, explaining general concepts and the use
      of each function. For each function, a popup guide is available via the F1 key.
   OPEN RAW: file is default-converted for view or edit via Fotoxx.
      Use popup menu to edit with Raw Therapee or Darktable and return to Fotoxx.
   VERSIONS: edited files have a version number, originals are retained by default
   EDIT PROCESSING: all calculations are done with 24 bit color (float data type)
      Output files can be JPEG (8 bit color) or PNG or TIFF (8 or 16 bit color).
   OPEN MPO FILE: Extract left/right files (3D pair) in .MPO file.
   VIDEO FILES: these are included in thumbnail galleries: click to play.
      Thumbnails use 1st frame by default, but can be set to any playback time.
   CYCLE WALLPAPER: change wallpaper at set intervals or at each new login.
      This uses a Fotoxx album or any folder with image files.