CactusViewer 2.0 is officially out!
This is a big one.
This update brings radical changes to the architecture, code structure, style, and intruduces a number of new features:


  • New render backend, replacing OpenGL with a Direct3D 11 renderer.
  • New handmade immediate-mode UI library that supports animations, themes, and subpixel antialiasing for text, replacing ImGui.
  • Windows Image Component decoders, opening the range of supported formats to pretty much anything Windows can open with their apps, plus the automatic support for any extra installed image codecs that WIC can support.
  • WebP codecs using Google's libwebp decoders, supporting both still and moving images.


  • Histograms with toggleable red, green, blue, and mix channels.
  • Live image value sliders to adjust brightness, saturation, contrast, and gamma.
  • A toggle to enable sRGB rendering.
  • Controls for rotating images without changing the file.
  • Support for reading EXIF metadata and displaying it, and correctly rotating JPEGs.
  • 3 UI themes to choose from in settings, including a light theme.
  • Fullscreen mode


  • An update to the coding style and naming convensions to something consistent, with better building scripts.
  • Moved the main repo to the current, under the master-2.0 branch, the previous version with ImGui and OpenGL is still available and be found under the branch: master-1.0.