I enjoy drawing diagrams by hand, either on paper or on a whiteboard. I would like to be able to take photos of these (using either a cellphone or a DSLR) and easily process them into reasonably professional-looking png files that I can post on my blog.
That is, I want to turn this:
with the minimum of fuss.
I did this one using Photoshop and Lightroom, but it was surprisingly hard and time-consuming to get the backgrounds to come out pure white without making any of the lines illegible. Since I'm planning to do this on a daily basis I would like it to be as much of a one-click thing as possible.
It seems that "Microsoft Office Lens" might be the kind of thing I need, but it's not available on a Mac.
These are the features I'm looking for:
- runs on Mac (required)
- crop and rotate (required)
- make the background pure white, even if there are shadows, without losing detail in the lines (required)
- make the black lines as close to pure black as possible without losing detail (required)
- preserve coloured lines (required)
- correct perspective distortion (desirable)
- good UI that makes the whole process as streamlined as possible (required)
- tools for managing and organising converted images (desirable)
A free solution would be ideal, but I don't mind paying for a good one.
Edit: I found, after a bit of experimentation, that I can get decent results quite quickly in Adobe Lightroom, as long as I take a bit more care about how the board is lit. (In my office, that means making sure the desk lamp isn't casting a shadow, and rotating the board so that it faces the window a bit more.) This means that my need for special software is less urgent, but it would still be helpful if someone knows something designed for this purpose, that runs on a Mac.
In case any future visitors would like to know, my Lightroom workflow is something like this. This is assuming a photo taken with a DSLR with good lighting and no perspective distortion.
apply "enable profile corrections" under "lens corrections" (to remove vignetting)
set the white balance using the eyedropper tool, on whichever part of the white background is most in shadow
under "basic", click "auto"
move the whites right up to +100 and the blacks right down to -100
adjust exposure so that the background is 100% white. (You can check by mousing over it - the RGB values are displayed underneath the histogram.) It should be just exposed enough to make all of the background pure white.
if the black lines look faded, increase the contrast until it looks okay, re-adjusting the exposure if necessary
if you can't get it to look good across the whole board because part of it is in shadow, set up a linear filter to increase the exposure in the shadowed part of the board
if the colours don't look good, increase 'vibrance' and/or saturation until they do.
This seems to work quite nicely as long as the original photo is lit reasonably evenly. My only issue with it so far is that it distorts some of the colours, tending to make orange look yellow, for example. (This can probably be corrected easily enough using the 'Color' panel, but that's an extra step.) I was able to get through 20 images or so pretty quickly, by using the sync changes feature for all but the last few steps.