All posts by markus

nomacs 2.4.4

this version is mainly a response to all your suggestions and bug reports – thank you for supporting us in increasing nomacs’ performance and usability. New features include:

  • Improved batch processing (you can now add images from multiple folders)
  • New Metadata HUD panel (you can dynamically choose entries)
  • nomacs respects your default proxy settings (e.g. when [manually] updating)
  • The portable version ships with a qss file (so you can customize almost everything)

the most important fixes are:

  • Default strings are now translated
  • Linux file sorting is (hopefully) fixed by now
  • Gamma correction for rescaling is now 16 bit (smooth gradients)
  • Zoom to Fit added (replaces ‘Reset Zoom’)
  • Saving of multiple tabs
  • UTF-8 encoding for image notes
  • General stability improvements

[EDIT] thanks to R3gi we have noticed that nomacs 2.4.4 has slow loading times on Windows 7. That is why we updated only these versions to nomacs 2.4.5. Sorry for any inconveniences caused!

— the nomacs team

Batch Processing

nomacs supports batch processing since version 2.4. You can open the bach processing from the Menu > Tools > Batch Processing. Currently there are four different processing modes (Copy/Rename | Image Format Conversion | Image Resize | Transforming).

First you can choose the directory and select the files you want to process. File selection is similar to the thumbnail preview (select multiple files using CTRL, hold SHIFT to select files consecutively or hit CTRL+A to select all files of a folder). You can additionally filter a subset using search terms or regular expressions (in the example below all files are chosen which start with a lower case character). After selecting the files to be processed you can click the Icon Add Files to the File List. If you open the File List Tab, you can also drop multiple folders to select their files for processing. Having selected the files to be processed, you can choose an output directory. The output panel allows you to choose the old filename or rename all processed files. The screenshot shows a file conversion where 87 files are converted to png.


The Output panel allows you to choose an output directory and rename/convert files. You can choose a custom filename. Do not forget to add a sequence number such that the filenames are still unique. The filename preview picks a selected image and shows the old and the new filename accordingly. If input and output directory are the same, images will be renamed in place. Otherwise the images are copied and renamed. This action will not change the image encoding.

the output panel
the output panel

Image Conversion

If you want to convert images to a specific output format (e.g. PNG) you can change the Keep Extension drop down to Convert To. Then select your preferred format. You can choose any format which is supported by nomacs.

batch convert images
batch convert images


Click the + next to Resize/Transform to apply an image transform. If you e.g. want to downsample all images of a folder, you can choose Long Side in the resize panel. Then enter the desired side length in pixel. This option will resize the image such that the width of panorama images or the height of portrait images will be set to the desired pixel length. If you check Shrink Only images which have a lower long side than the desired length will not be resized.

batch resize
batch resize

The Transform panel allows you to rotate or flip all images. The gray text next to the panel title indicates if a panel is active or not. The example below shows a configuration which resizes all images by 50% and then rotates them by 180°.

batch transform
batch transform


After you configured the batch processing according to your needs you can hit OK. A progress bar will appear which indicates the percentage of images already processed. If you notice a wrong configuration, you can cancel the processing. All images processed will stay the same then but the processing is stopped immediately.

processing images
processing images

All processing actions are logged. Choose Show Log to see the status of the processing. You can see the status of every batch module and check if it was processed successfully. Please check the batch configuration before Processing especially if you check Overwrite Existing files since these actions cannot be reverted.

log file
log file

Overview Panel (Zooming)

The Overview Panel (Menu > Panels > Overview) enhances zoom and pan. The blue rectangle shows the current viewing area. You can pan to a specific location by dragging this rectangle to the desired position. The scrollbar at the bottom allows you to zoom. If you want to zoom to a desired factor (e.g. 600 %) you can mark and replace the text accordingly.

Overview Panel
Overview Panel

GSoC 2015

nomacs was not accepted for GSoC 2015. We would like to thank all students who were willing to contribute to nomacs. But don’t forget, it’s open source – so you are always welcome to contribute : )

– the nomacs team

nomacs 2.4.2

fixes some major bugs of the 2.4.0 release. These fixes include:

  • Image Manipulations are fixed now (black images on e.g. gamma)
  • Resize with gamma correction (black images if gamma was checked)
  • Crash fixed (if reload occurred after an image resize)
  • Batch Processing fixed
  • GIF movie toolbar fixed (thanks to alyosama)
  • Translations updated (thanks to all translators)

– the nomacs team

nomacs 2.4.0

the new 2.4.0 release is a milestone in our development. First, it will be the last feature release which mainly supports Qt 4 (again the numbers align perfectly: 2.4). Second, it is probably the hugest feature release ever. The most important features include tabs, an all-in-wonder batch processing, and an improved thumbnail preview. Good news for all Windows XP and Vista users (who should definitely update their system : ), we compiled nomacs a last time for these systems. Here is the full changelog:

  • Batch processing (you can try it by clicking Tools > Batch Processing)
  • Image tabs (open multiple images within different tabs)
  • Thumbnail preview improved (copy/paste delete/rename is now supported)
  • Zoom panel improved (you can now chose a specific zoom level)
  • Olympus RAW added
  • Convert to grayscale added (thanks to shreelock)
  • Faster directory loading (especially if you have many images in a folder)
  • Gesture improvements
  • Saving of images from archives (e.g. zip, docx) is now supported
  • File sorting improved (Unix-based systems only)
  • Stability improvements

– the nomacs team

But which image format should I take?

Since we see a lot of people choosing the wrong image formats on a daily basis, we have created a short cheat sheet for you. Though JPEG is probably the easiest way to archive your pictures, there are several incentives to choose another image format depending on the image content or purpose. (You can also download the cheat sheet)

Image formats for photos
Image formats for photos
Image formats for illustrations
Image formats for illustrations

– the nomacs team

Windows 10

We have tested nomacs on windows 10. Everything works out as expected, except that the Frameless View seems to be obsolete since Microsoft removed the window frames.

— the nomacs team

nomacs running on windows 10
nomacs running on windows 10


Want to Support nomacs?

we would need your help for increasing the support of nomacs on different OS:

  • OSX Build in addition to Petr’s MacPort packages we would love to distribute dmgs of nomacs.
  • Linux Plugins we are seeking for someone who can help us with the packaging of plugins for Linux.

If you have experience in any of these fields and want to support us, you can leave a reply to this post or write us an e-mail (

– the nomacs team