ShiftN Portable

Automatic perspective correction of architectural photos

ShiftN corrects converging vertical lines ("falling buildings") in photos taken with the camera tilted upwards. It detects straight lines in the image, computes a perspective correction that makes the near-vertical lines parallel, and saves the corrected and trimmed image at full resolution.

This is the portable version: it runs from a USB drive, a cloud folder or any other folder, and leaves no settings behind on the computer. It needs 64-bit Windows.

Getting started

  1. Start ShiftNPortable.exe (or ShiftN from the PortableApps.com Platform menu).
  2. Load a photo: File > Open, drag and drop, or Edit > Paste. JPEG, TIFF (8 and 16 bit), PNG (8 and 16 bit) and BMP are supported.
  3. Choose Start > Automatic correction. Detected lines are drawn in the image; click a line to exclude it (or include it again) and use Start > Re-optimize.
  4. Fine-tune with Start > Adjust correction if needed.
  5. Save with File > Save results or File > Save as.... Output format, JPEG quality, trimming, sharpening and the file name suffix are set in Options > Type of output.

File > Batch processing corrects many photos in one go. The language (English, German, French, Spanish) is selected in Options > Language. On the first start, ShiftN Portable uses the language of the PortableApps.com Platform (English if the Platform language is not one of these four).

Help

The full ShiftN manual opens with Help or F1 in the selected language.

Settings

All settings are stored in the Data\settings folder of ShiftN Portable (ShiftN.ini and ShiftN_profile.ini). To reset ShiftN to its default settings, close it and delete these two files. Updates keep the Data folder.

License and source code

ShiftN is free software by Marcus Hebel, licensed under the GNU Lesser General Public License version 3 (see Other\Source\COPYING.LESSER.txt; COPYING.txt contains the GNU General Public License it refers to). The complete source code is included in Other\Source\ShiftN_Source.zip.

ShiftN uses the Independent JPEG Group's JPEG software, LibTIFF, libpng, zlib and jhead.

In 2026, parts of the software were refactored and modernized with assistance from AI-based development tools (Claude). All modifications were reviewed, integrated, and tested by the original author.

Homepage: www.shiftn.de