How to

Use One Photo Viewer

Basic usage
Full list of keyboard shortcuts
Additional config file settings

Set One Photo Viewer as ​default photo viewer

1. Open Windows start menu and click the settings icon (the gear).
2. Click “Apps” then “Default apps” and click on “Photo viewer” selection.
3. If you already have One Photo Viewer install then select it and your done. Else choose “Look for an app in the Store” and find One Photo Viewer there.

Sort images as in Windows File Explorer

By default images is sorted by name in OPV. This can be changed so images is sorted as in Explorer. This is not default because for some users it makes OPV start very slow or become unresponsive for a while. For most users it doesn’t affect performance.
To view images sorted as in Explorer, press F2 to open config file then set this setting to False and click Save:
<add key=”shell32_sort_disable” value=”False”/>

RAW format support

Extend format support by installing Raw Image Extension from Microsoft store. Most RAW formats can then be viewed in One Photo Viewer. But no guarantee it will work.

WebP format support

One Photo Viewer have support for WebP image format if codecs is installed. But no guarantee it will work. Download and install WebpCodecSetup. Only viewing WebP still images is supported, not animations.

HEIC / HEIF format support

Install HEVC Video Extensions (no longer free on MS Store, cost $0.99) and HEIF Image Extensions to get HEIC image support in One Photo Viewer. But no guarantee it will work. If the extention do not work the first time try reinstall or uppdate HEIF Image Extensions.

Batch process images

See how to use keyboard macros to batch process images here

Reset settings file

If the software does not behave as it should, for some reason. You can reset the settings to default values by pressing SHIFT during start of the software. Best to start the software from Windows start menu. If holding shift while double click on an image you may accidentally open a whole bunch of images.

Set background to arbitrary color

Pressing Ctrl+Alt+Shift while click and drag left mouse over the image will change the background color to the color beneath the mouse. Or you can edit the config-file by pressing F2 and edit key=”background” value=”DarkRed” for example. See X11_color_names, but remove spaces in color name. If you want same background at every start but still be able to change it temporary you can add the lock=”true” attribute to the config file value (see example at top of config-file).

Use eraser tool

Pressing Ctrl+Shift while click and drag left mouse over the image will set a square beneath to background color. First select background color black, white, transparent or arbitrary color see above. If you using transparent background save the image in PNG format. While holding Ctrl+Shift you can change the eraser tool size by the mouse wheel (v1.12.0.0).

Erase a color

Pressing Ctrl+Alt while click and drag left mouse over the image will set the color beneath to background color. First select background color black, white, transparent or arbitrary color see above. If you using transparent background save the image in PNG format. This feature is not so useful for photos, since only the specific color beneath the mouse will be affected. But can be useful for editing screenshots and other computer generated images. While holding Ctrl+Alt you can increase the size of area measured by the mouse wheel, but it becomes very CPU intensive in increased.

Make stylized text

There is an extra feature built-in to OPV that generates stylized text, from any text file, based on a set of character images you easily edit yourself. For more info on this goto onephotoviewer.com/stylized-text