🧩 ujc to png

How to use

On this page, nonogram authors can easily convert their own designs from the .ujc files exported from the game to normal .png images as follows.

• Step 1: Export your nonograms from the game

  To start, open the Nonograms Katana Android app, then select the Settings icon in the top right corner (see the wiki for help). Once in the settings, open the menu named Other and select Save progress to file (zip) to export an archive of your data.

  As another option, you can use the Share feature available in the My Nonograms screen to save a copy of a nonogram (see the wiki for help).

  Finally, the .ujc files can also be found in your device's internal storage in the Android/data/com.ucdevs.jcross/files/puzzles folder.

• Step 2: Extract the exported archive

  Using your preferred file manager, extract the NonogramsKatana.zip archive so that the folder named MyNonograms becomes accessible. This folder contains all your nonograms saved as .ujc files.

• Step 3: Drag and drop your files below

  Now, you can drag and drop the .ujc files in the area below; alternatively, you can click on the same area to open a file picker dialog where you can select the files. After a short while, the converted images will appear in the gallery below ready to download.

FAQ

• How does this app work?

  This app analyzes the .ujc files generated by the game and extracts the contained png images that represent the nonogram pictures.

  To learn more, you can review the source code on GitHub.

• Who is this app for?

  This app is for nonogram authors who want to backup their own designs and have them available as images.

• Are my nonograms private?

  Yes. This app works entirely inside your browser and no file ever leaves your device.

• Can I download nonograms made by other authors?

  No. To respect their work, this app does not allow you to download nonograms made by other authors.

• How many nonograms can I convert?

  As many as you want. However, the more nonograms you process together the slower the conversion process will be, especially on less powerful devices.

• Why does nothing happen after I select the .ujc files?

  On less powerful devices, the conversion process can take a few seconds or more. Either wait a little before retrying or convert fewer nonograms at a time.

• Why do some images have transparent backgrounds?

  When the Recolor images option is not selected, images are extracted as-is from the .ujc files, which internally represent the background color of colored nonograms as transparent.

  To fix the final colors, enable the Recolor images option. However, due to the way that browsers work , this is a lossy operation and the final colors may be slightly different from the original ones you selected in the game editor.

• Why are the extracted images so small?

  If the Scale images option is set to 1, the final image dimensions correspond to the original dimensions of the nonogram. For example, a 20x20 nonogram becomes a tiny 20x20 pixels image.

  To save images in a larger format, increase the value of the Scale images option. For example, scaling a 20x20 nonogram by a value of 25 produces a larger 500x500 pixels image, since 20*25 = 500.

  Note that, similarly to the Recolor images option, this is a lossy operation and the final colors may be slightly different from the original ones you selected in the game editor.

• Why does the Border radius option not work?

  Make sure you are using the latest version of a supported browser and try increasing both the Scale images option and the Border radius option to a high value like 50 to verify that it works.

• Why are the Dropzone, Options, and Gallery sections not visible?

  This can happen when something goes wrong when loading this app. Make sure you are using an updated and supported browser that has JavaScript enabled and try reloading the page.

• Can I directly import png images into this app?

  Yes. Just drag and drop them into the dropzone or select them in the file picker. After that, you can manipulate them as usual with the available options.

  For example, you can use this app to add grid lines to your images. If this is the case, we recommend using gridify.it if you need a way to add a grid to your pixel art images.

• Can I save my nonograms from the Nonograms Katana iOS app?

  No. Unfortunately, the Android and iOS versions of the Nonograms Katana app are different and the iOS version does not currently provide an option to export your nonograms to a local file.

  If you find a way to export or share .ujc files from the iOS app, please open an issue (see the last question) so that we can update this answer.

• I found an error / I want to ask another question.

  Please open an issue on Github, it's the fastest way to have your question seen.