Lew's Picture Viewer

The same application is also available under Python. The Python version is very similar in layout and features to the C#/WPF version. Main differences and other notes at the bottom. Available as python script (see below) and as a self-contained MacOS app (unzip it and move LpvWx.App directory to your ~/Applications directory).

For a quick overview, I have a short video (10 minutes) introducing the main features. Bad audio unfortunately.

Both versions are now essentially completed. Some functions may seem like unnecessary features, but were done to explore some area, such as the slide show to explore timers. Other areas might still not be quite optimal, such as GUI focus management.

It has features which may be useful to a photographer, such as viewing some or all images in B&W. Something I haven't seen in any other viewer (altho I'm sure there are some, no need to send me a list).

Some of the main characteristics compared to other viewers I've used:

• Allows to view all images in B&W, or upside-down. This can be helpful to photographers in evaluating the potential of an image.
• Flexibility in adding images to be shown.
  • Can drop directories, text or image files onto LpvDotNet.exe or the open application to add images (none of the picture viewers I have tried support latter).
    - For directories, all images files are opened
    - Text files are parsed for lists of images to open.
  • Can also load images from the Web (an experiment, not something really useful).
• Image manipulations (rotation, conversion to B&W, &c) don't update the image files on disk (as some "viewers" do). But they are remembered while the application is running, and if you come back to an image, it will have the same changes applied.
• Can copy original image to clipboard, can launch editor on image.
• Allows you to add notes to images. These notes can be saved in a (Unicode UTF-8) text file.
• Has a simple zoom-in feature (click in image).
• Allows basic brightness/contrast adjustments (not saved to disk!).
• Has a feature to show clipped highlights / blocked shadows (areas full white or full black).
• Does not pre-load any image in memory, they are loaded on the fly when being displayed. So the image set can be large without much risk of resource shortage.
• Does not use the Registry or leave other traces (except the text files).

The set of images is organized in a ring (circular buffer), with an blank "wrap point" (the "Home" button) between the last image and the first image. The initial order is that of the command line parameters. Thereafter, the set can be sorted by date, simple name, and a few more. Images added after initial load are added after the current image, or after the last one if no current image (ie. on the wrap point).

Lpv.NET understands usual image file types supported by WPF: JPEG, PNG, TIFF, &c, as well as shortcuts.

Lpv.NET also understands text files containing names of image files (and even HTTP URLs). For example, the following text file would open four images:

c:/users/pilewis/IMG_1946.jpg
R:/Pierre/IMG_1956.jpg
piano/IMG_1994.jpg
  (marked)
http://leware.net/photo/IMG_5305-G.jpg
  Notes=Some text that describes image

The .lpv text file can also contain notes and/or markings, as shown above.

When walking a directory, only images are considered, no recursion deeper into sub-directories or text files. It would be possible, but there is the risk of opening (much) more than wanted. Recursion is done from text files (so a text file could contain names of directories or other text files) -- be careful (esp. of loops! no checking).

Layout:

• At the top, we find the menus and a message area (typically contains the full path of the image).
• On the left, the various buttons.
• At the bottom, there is a short summary of the current image including file date, size in pixels, and the EXIF date if available, and an area for annotations on the image (that are stored in the "notes" file discussed below).
• The rest of the window is the image area. Images are normally scaled to fit if needed, but not expanded beyond 1:1.

Menus:

File	Saving notes, loading new images, &tc
File -> Save Notes	Save list of images and associated notes
File -> Save Notes As...	Save list of images and associated notes
File -> Load...	Load new images (can select multiple files)
File -> Load URL...	Load image from URL
File -> Load Test Image	Load test image from http://www.photofriday.com/calibrate.php
File -> Clear Set	Clear image set
File -> Exit	Exit Lpv.NET
Set	Actions on image set
Set -> Sort Name	Sort image set based on image name
Set -> Sort Date	Sort image set based on file date (using EXIF date would be confusing, as not all images have that date)
Set -> Sort Flags	Sort image set based on the two marks: "marked" images come first, then unmarked images, then "deletable" images
Set -> Sort Notes	Sort image set based on notes
Set -> Sort Full Name	Sort image set based on full path name of image
Set -> Sort Size	Sort image set based on file size
Set -> Show All in Greyscale	Toggle view of all images as greyscale or color
Set -> Show All Upside Down	Toggle view of all images upside-down or normal
Set -> Show Over/underexposure	Show (or don't) areas of the image where we have clipped highlights / blocked shadows -- Tab key can also be used to toggle this
Set -> Show Deletable Images	Show (or don't) images marked for delete
Set -> Start Slide Show	Start or stop slide show (randomized)
Image	Actions on a single image
Image -> Copy Info	Copy some info (including full path) on current image to clipboard
Image -> Copy Bitmap	Copy original image bitmap to clipboard
Image -> View Metadata	View image metadata (if available)
Image -> Edit	Launch program to edit image (see below)
Help
Help -> About	About information
Help -> Help	Show this page

Buttons:

Prev	Show previous image. With shift, show image from previous date (see details below).
Next	Show next image. With shift, show image from next date.
Home t	Position on "wrap point" on ring, after last image and before first.
Three rotate buttons	Three buttons to rotate image -- no change on disk of course. Lpv.NET will try to read the proper orientation when the image is loaded for the first time.
Grey/color	Toggle B&W and color for this image -- no change on disk.
(two sliders)	Two sliders to change curves -- no change on disk. The first is roughly brightness, the second, contrast. Work in progress.
Reset	Reset above two sliders to their center positions.
[Move] to end	Move current image to end of set, and show next image. Can be used as a crude manual sorting mechanism. To position on end/begin of image set, use "Home" button.
Mark	Mark image (for whatever purpose). A green checkmark signals this. An image cannot be marked and deletable at the same time.
Deletable	Mark image to be deleted (deletable) -- no change on disk of course, but this flag will be in the output notes file (and the actual delete can be scripted from there). A red cross over the image signals this.

Note: if you make the window too small, some of these controls will disappear.

Keyboard:

Left/right arrows	Outside "Notes" area, show previous/next image. With shift, show image from previous/next date (see notes below). In "Notes" area, move within text. With shift, position on beginning/end of text.
Page up/down	Show previous/next image. Works whether in or outside of "Notes" area, useful when adding comments to many images in succession.
Up/down arrows	Outside "Notes" area: nothing for now. In "Notes" area, recall recent notes (useful when many images get same/similar notes).
Enter	Switch focus to/from the "Notes" area. In some cases, you may need to use the mouse to switch focus to the "Notes" input area.
Backspace/del	Outside "Notes" area, toggle "mark for delete" of this image.
Tab	Outside "Notes" area, toggle "Show over/underexposure"

Mouse:

• Clicking inside an image will zoom in to full size (1:1) around the point on the image. Clicking again zooms back out so whole image is visible. Someday we might have finer grained control over zoom amount and/or panning.
• Other than above, the mouse behaves as expected.

Other notes

• The image set can be "unsorted" (when initially loaded, when images are added), or it can be sorted in a few different ways. The significance of shifted next/previous depends on the sort:
  • if sorted date: show image on next/previous date (more than 7 hours between two images);
  • if sorted notes: show image on next/previous change of first word of notes (eg. it could be a theme);
  • if sorted full name: show image on next/previous change of directory;
  • any other order or unsorted: show image on next/previous date (may or may not be useful).
  Sorts should be stable.
• When on the wrap point ("Home" button), one can enter simple search in the "Notes" area at the bottom. On hitting enter, Lpv.NET will search for the string both in full file name and in comments. Simple search (not regexp), case insensitive. To repeat the search, hit F3.
• Marking images for delete does not modify anything on disk (in particular, the image is not deleted). Images so marked will be identified in the saved text file, along with the notes. A script can then be used to extract a list of just those images. I may provide something.
• Environment variable IMAGE_EDITOR must be set to the path of an image editor for the "Image -> Edit" menu item to work. For example:
    IMAGE_EDITOR = C:\Program Files\Paint.NET\PaintDotNet.exe
• There are no thumbnails right now, so navigating large image sets can get difficult. One approach that can help is the search facility mentioned earlier. It is also possible to sort on date, then use the shift left/right arrows to position on previous/next date (the current definition is that the app goes in the requested direction and stops on an image which at least 7 hours later or earlier).
• Clipped highlights and blocked shadows are shown by red and blue respectively, when all three color components reach maximum or minimum. I believe this matches Lightroom's behavior.
• The sliders and the display of clipped highlights / blocked shadows is done thru a GPU pixel shader, one more fun thing to learn.

Errors and other unusual circumstances

• When on the wrap point ("Home" key), the message at the top says how many images are in the set. It may also report "missing" images. The latter are files that could not be opened for some reason or other. The names of missing images will be output as comments in the notes file.

Some known challenges

• Tested on just a few PCs so far (Win7, Vista).
• For most of the world, DPI of a photo is unimportant (see my DPI rant). But, unfortunately, it is for WPF. The same image, with the same number of pixels, will (by default) display differently depending on its DPI value. Took me a while to figure out a way to code around this.
• A more significant DPI is that of the display. I expect some surprises on a display other than that of a standard PC at 96 DPI, eg. on a Windows tablet.
• On writing good bug reports.

Notes on the Python version

• It is based on Python 2.7 (will not work in Python 3) and wxPython 3.0. If module PIL is available, it will be imported and used to extract some EXIF data. I used Python 2.7 because wxPython was not yet ported to Python 3 when I started this work.
• This version has been tested on Windows, Linux and MacOS (with the usual small surprises -- wxPython uses the native GUI environment).
• The TAB key is used to repeat a search (F3 not available on Mac). In the "Notes" field, it moves to next image (on Mac, I have no PageUp/Down keys), or previous if shift+TAB.
• Instead of two sliders for brightness and contrast, we have a single slider corresponding to gamma, the one "adjustment" option that is available in wxPython's wx.Image class. I may revisit this later.
• Currently no support for showing clipped highlights / blocked shadows, same reason as above.
• "Move to end" is renamed "To end" (to avoid an ugly wider button in some environments).
• This version will try to read the EXIF tags for comments and update the "notes" if available.
• A few new options were added to the slide viewer: "linear" shows the images in order (as they are in the ring), and "once linear" does the same thing but stops at the end. While the slide show is running, the space bar can be used to pause and resume it.
• Unicode (multi-lingual) support within Python (2.x anyway) is confusing (see for example this summary). The application works for me on a French iMac, with accents in file names and in comments, but problems are certainly still possible. Environment variable LPV_ENCODING can be set to the local encoding, for example:
    LPV_ENCODING=iso-8859-1
• The python code still writes too much to stdout, will get better as debugging ends.

• To simplify things, I define a script, eg. ~/bin/lpv, to start the viewer (the example shows Adobe PSE, but I use Gimp!):
    #!/bin/ksh
    export IMAGE_EDITOR="open -a 'Adobe Photoshop Elements'"
    python ~/Lpv/LpvWx.py $*
  Then, in a Terminal window, I can launch the viewer as needed with something like:
    lpv imageDirectory someOtherImage.jpg
  

• The package can be unzipped either under the user's own ~/Applications/ directory, or the system's /Applications directory (latter might require sudo powers).
• If the application misbehaves and won't go away, try
      killall LpvWx
  in a terminal window. Error messages should be visible in the "Console" application, and you can send them to me.
• If you have Gatekeeper, MacOS will refuse to start it. You can control-click on the application (LpvWx.app) and then Open. Signing this application would require that I become a registered developer with Apple, the cost is over 100$, and I would never recover this investment :-).
• You may wish to associate .lpv files with this application, and maybe even some image file types.
• A sample IMAGE_EDITOR setting on MacOS might be "open -a Gimp" or "open -a 'Adobe Photoshop Elements'" (without the double-quotes); this can be set in file .../LpvWx.app/Contents/Info.plist (just edit line 8 with any text editor to set the visual editor you prefer).

Closing remarks

If you have suggestions, I'll listen. But basically, the tool is mostly as I want it... Still, I might try to add thumbnails, and have more control over zooming.

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