To print cleanly and smoothly, a bitmap image must be scaled to an appropriate 'pixels per inch' size so the individual image pixels can't be made out. The standard rule of thumb is 300 pixels per inch (or ppi, often referred to as dpi), so to fill a one inch-wide area your image should be at least 300 pixels wide.
However, this assumes you know how wide (and tall) an InDesign graphic frame is in inches – which is standard only in the US – and are also happy to do the calculations yourself.
To install, copy the unzipped script document to Scripts / Scripts Panel inside your Adobe InDesign application folder. You'll find Resolver Script in Window > Utilities > Scripts, in the Application section.
The original Resolver app will gain additional features soon, but either of these does the job right now. And if you're a Windows InDesign user you need Resolver Script.
(Or if you have a PayPal account this PayPal.me link is quicker.)
Tips are used to help offset the cost of my software prototyping and development tools and are greatly appreciated.
FAQ 1: "Which Resolver do I use and how do I run it?"
Resolver is a standalone app that floats above InDesign and reports on what you have selected. This currently only works on Macs. To open it, double-click the app icon.
Resolver Script is a pure ExtendScript tool. This works in both Mac and Windows versions of InDesign. To open it, put the .jsx file into the InDesign app folder's Scripts/Scripts Folder, er, folder, then open it by going to Window > Utilities > Scripts and opening the Applications folder in the Scripts panel.
FAQ 2: "How do I use Resolver?":
FAQ 3: "Okay, what's this resolution stuff?"
Bitmap images are simply grids of coloured squares – the pixels. If the grid is scaled down small on the page we can't make out the pixels, and we call it high resolution. If we scale the same image up very large on the page the pixels are larger and more obvious... and we call it low resolution.
Any image can be high or low resolution, it just depends on how big we make it. If you want to know how large an image has to be in pixels to fill a particular frame in InDesign and be at least 300 ppi (or 600, or 240), Resolver will tell you instantly.
300 ppi is the industry-accepted standard for image resolution in print. This assumes the image is photographic and the print process is commercial offset litho onto good-quality paper stock, or an equivalent inkjet output. This is good enough for almost all work, however... If your image is line artwork (such as scanned black & white diagrams) it should be scaled to a higher resolution – select 600 ppi from the menu. If your pages will be printed for posters or wall-mounted exhibition display (where the typical viewing distance is further than normal magazine or book reading distance) or your paper is uncoated and a little absorbent you can get away with a lower resolution – select 240 ppi from the menu.
FAQ 4: What's the name about?
Resolver is a 'resolution solver' – it solves the conundrum of what image size you need to achieve a cetain resolution in a particular graphic frame. (Before you ask, it's not called 'RSLVR' because we're designers, not hipsters...)
First-time launch: Mac users may need to open this app the first time by right-clicking/control-clicking and selecting 'Open'. This only happens once.
This software is free to use, of course, although tips help me pay for my development costs. Bug reports and questions are also welcome – you can find me on Twitter (@thatkeith) and Facebook (https://www.facebook.com/thatkeithmartin).
— Keith Martin
Why no Windows version?
This uses AppleScript to get the selected object type and dimensions from InDesign. I will experiment with VBScript in Windows if this would be useful (so do let me know), otherwise I'll leave this as a Mac-only utility.
I'm considering adding a feature to tell users what pixel size an image files is – and then perhaps to automate placing the image into a frame. Let me know if this would be of interest.