Nōtan is a Japanese design concept involving the play and placement of light and dark elements next to the other in the composition of art and imagery. The Yin Yang symbol is an example of this design philosophy. The use of Nōtan in art composition is a powerful tool to help the artist identify the structure of the light and dark portions of the image they want to incorporate into their project.

If you are curious about how to adapt NotanIzer into your workflow here are a few video tutorials made by users of our app

Using NotanIzer is fairly easy. Here are the basic directions which you can also find in the app using the info button on the bottom right.

How does it work?

First import an image using the camera or by selecting one from your photo library. On the Mac version you can also import a file using the functions of the File menu or even drag and drop and image. The app will make a local copy of the image and use that. One question we get often is how do I close the image? Simply, you don’t. It will always open the last image you looked at and when you want to to change to a different one, simply open it and it will replace the current image.


Notan describes the Japanese notion of the difference between light and dark, similar to the Yin Yang symbol. The Notan function simply divides your image into black or white. It starts at the 50% color value but you can adjust the slider to move it back and forth. Any value above the slider position will be painted white, while below will be painted black. A lot of detail emerges from an image this way.

Black and White

Converts the image to gray scale. Helps with the shapes and overall composition of the image without getting lost in the color.


The original color version of the photo so you can reference it.

3 Level, 4 Level, and Levels

The 3, 4 and Levels controls, similar to Notan, splits the image into 3, 4, or up to 10 bands of black, gray, and white values based on the number of levels you have selected with the slider or the increase/decrease button on Levels.

All the sliders have a +/- button on the left to fine tune the exact number you want.  On sliders with multiple handles like the 3 and 4 level, the selected one will be white while the none selected ones will be dark blue.  The +/- button will only work for the selected (white) slider button.  On the 3 and 4 level sliders, the minimum value is 0 for the far left slider and the max value is 100 for the far right one, with a minimum of 10 between each slider.

On IOS devices you can use the share button on the bottom right to export your work in various ways.  Make sure photo acceess is set to All Photos so that you can share and save your work to your photo library. On Mac’s the main share button in on the top right with more options under the File menu item.

We hope you enjoy NotanIzer and if you have any suggestions, bug reports etc, feel free to let us know!