Photoshop Guide

This guide will help you get the most out of Lazy Nezumi Pro if you're using it with Photoshop.

It will also cover the most common support issues.

Installing Lazy Nezumi Pro for Photoshop

Important: When choosing a folder location for installing Lazy Nezumi Pro (LNP), do not choose your Photoshop folder, as this will cause problems. Instead, install it to its own folder (for example, in C:\Program Files (x86)\Lazy Nezumi Pro).

LNP has two main components:

  1. The main app (LazyNezumiPro.exe), with which the user interacts with directly to control presets and settings.
  2. The plugin (MouseHookPro64.8li), which is loaded into your art application and performs the actual processing requested by the user settings.

If you intend to use LNP with Photoshop, be sure to check the "Photoshop plugin" option when installing LNP. This will install a link in your Photoshop plugin folders so that Photoshop can load the plugin directly at startup.

Once the plugin is loaded, LNP will automatically attach itself to your document windows, and process your lines when you draw in them.

Here's how to verify that the plugin has been installed correctly:

  1. Launch Photoshop. LNP's main app should start automatically, and it will show "Photoshop plugin loaded" in the bottom status bar. (If you don't want LNP to start automatically, you can disable this via Settings/Edit Photoshop Options.)
  2. In Photoshop, open the Help/System Info menu. In the plugins section, you should see an entry for Lazy Nezumi Pro or its plugin file name MouseHookPro64.8li.
  3. In newer versions of LNP, you can see the list of apps in which it has been loaded via the File/Attach to Window menu. There should already be a tab there for Photoshop.exe, and the Plugin Status should say "OK (plugin loaded by PS)".
LNP Attach to Window

If it looks like the plugin hasn't been installed correctly, please see the next section.

Installing the Plugin Manually

If you have a "portable" version of Photoshop, its installer probably won't have installed the correct folders and registry keys, and LNP's installer won't be able to find it. In this case, you will have to install the plugin manually:

LNP Manual Photoshop Plugin Installation

Updating Photoshop

For versions 22.07.20 and newer of LNP, the installer copies a plugin link in Adobe's common files folder of your system. This folder doesn't get destroyed when updating Photoshop, so you shouldn't have to reinstall LNP afterwards.

For older versions of LNP, you will have to run its installer again after updating Photoshop, so that the plugin file can be copied to the new Photoshop plugin folder. If your version of LNP is older than Photoshop, you may have to install the plugin file manually, as explained in the previous section.

Photoshop Tools

While LNP can work with many art applications thanks to its Attach to Window function, it has the best integration with Photoshop, as it makes use of its plugin API.

Thanks to this API, LNP is able to know which tool you are currently using. This lets you configure the list of tools you want LNP to work with or ignore. If you uncheck tools from the list via Settings/Edit Photoshop Options, LNP will be in bypassed mode (effectively off) when you switch to one of these tools, and will show toolName (OFF) in the status bar of the main LNP window. This will simplify your workflow as you won't have to manually turn LNP off and on again all the time.

LNP Photoshop Options

Please note: Photoshop does not always notify its plugins about tool changes. If you ever have LNP on but find it isn't processing your lines as intended, check the status bar. If you see toolName (OFF), and that tool doesn't match the one you're using, try changing tools a couple of times before going back to your drawing tool so that it can sync up again.

Ruler Canvas Tracking

The plugin API also allows LNP to track the position and zoom level of your opened document windows, and adjust the center and zoom level of its rulers accordingly.

However, please note that you should avoid rotating your canvas while using the rulers. Since canvas orientation isn't sent to the plugin, this will cause the rulers to not be aligned with your scene anymore.

The center of a ruler in relation to your document is sent to your currently active LNP preset. So don't forget to save your preset after you've setup your ruler. If you do, the ruler center position will be resent to the plugin when this preset is reloaded (at startup, or if you click the Discard Changes button).

If you're using older versions of Photoshop such as CS5 or CS6 with a high-DPI screen in Win10 or Win11, you may run into an issue where the centers don't track correctly, and are offset after panning or zooming. In this case, try unchecking the Canvas tracking: use DPI option via Settings/Edit Photoshop Options, which was added in version 19.10.22.

If you're using an LNP version older than 18.03.08, or using it with non-Photoshop apps, you will have to set the Canvas Zoom parameter of the Rulers section yourself so that it matches your current document zoom, and then realign your center position with a pre-drawn center mark in your document.

Wintab vs Windows Ink

Recent versions of Photoshop use the Windows Ink API to get data from your tablet. You must make sure that this is enabled in your tablet settings. For Wacom tablets, start the Wacom Tablet Properties app, create an entry for Photoshop, and then check Use Windows Ink in the mapping tab, as shown in the screenshot below. If you do not check this option, Photoshop will treat your pen as a mouse, it will receive no pressure data, and you might get jittery lines from the low-resolution position data it receives.

Wacom Tablet Properties

Photoshop CS6 and older use the Wintab API instead. For these versions, you will want to uncheck the Windows Ink option in your tablet settings.

Be sure to check out the Tablet Setup Guide for more info about tablet APIs, and other tips and tricks!

Windows Ink Pen Lag

Unfortunately, Photoshop's Windows Ink implementation is buggy. (And still buggy as of September 2023!) You will encounter lag when using your pen in certain windows. This can be seen here with the brush size slider:

LNP version 23.06.20 has an experimental fix for this issue. Simply check the "Fix Windows Ink pen lag" option via [Settings/Edit Photoshop Options] in LNP. (This option is off by default, as it can have some side effects. If you do try it, please let me know if you run into any problems so that I can try to address them.)

Wacom settings window with the Windows Ink option.

If you'd rather not deal with Windows Ink at all, there's an alternative. There is a way to make recent versions of Photoshop use Wintab instead: place this PSUserConfig.txt file in your PS preferences folder: %APPDATA%\Adobe\Adobe Photoshop 2023\Adobe Photoshop 2023 Settings. If you do this, it's recommended to also uncheck Windows Ink in your tablet settings. Note that this will not work on Surface style machines that don't have Wintab drivers.

It's worth mentioning that at some point, the Coolorus plugin was installing this file without asking the user, to avoid this Windows Ink pen lag issue. So if you do want to use Windows Ink, or don't have a choice (Surface machines), be sure to remove this file.

CS6 Jitter Bug

The tablet input implementation in versions of Photoshop up to and including CS6 was never great. One of the most annoying issues was known as the Jitter Bug. This would manifest seemingly randomly, and would cause your lines to be jittery or aliased.

After lots of investigation, a fix for this issue was provided in version 16.06.03 of LNP. (And despite communicating my findings to Adobe, they never bothered to fix this themselves...)

So if you're still using CS5 or CS6, make sure you have the Fix Jitter Bug option checked in Settings/Edit Photoshop Options (changing this requires restarting Photoshop and LNP).

LNP Photoshop Jitter Bugfix

Offset Lines on High-DPI Screens

If you're using Win10 or Win11, be aware that older apps such as CS6 will have their windows automatically scaled if you're on a high-DPI monitor. The problem with this is that the Wintab driver will not know about this scaling, and will report a conflicting desktop resolution to the app. This usually results in lines that shoot in from an offset position when you start drawing. (Note that it's possible you'll only notice this issue when using LNP's Jitter Bugfix.)

To fix this, you have a couple of options:

  1. Prevent Windows from scaling your app window. You can do this by clicking your application's executable file, selecting properties, then clicking Change high DPI settings in the compatibility tab. Then check the Override high DPI scaling behavior, and select Application. The problem is that your app window might then become too small to read.
  2. Uncheck LNP's Fix Jitter Bug option, and check the Tablet Mouse Mode option via Settings/Tablet Options. The offset lines should go away, but your line quality will be affected, especially when drawing while zoomed out.
  3. Update to a more recent version of Photoshop that is DPI aware (and deal with the various Windows Ink issues instead).

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Lazy Nezumi is a trademark of Guillaume Stordeur. Developed in the USA.