Cleaning Digital Photos of Drawings

One of the big hits from the IFVP 2006 Conference was the Tech Session. There was quite a buzz about the Photoshop demonstration on "cleaning" photos of graphic recording artwork.

Click below for a step by step guide on how.

[Click on the thumbnails for larger views.]

Using Photoshop, open the image you'd like to clean. For best results, choose an image with  evenly distributed light. Avoid those with hot spots (from a flash) or dramatic shifts in light and shadow.

From the menu at the top of the window, select Filter > Other > High Pass.

In the High Pass window, experiment with the settings that best create an even, grey background. The key is to retain the most accurate color range on the drawing as well. Suggested range: between 75 and 125.

Next, adjust the levels of lights and darks.
On the top bar menu, select Image > Adjustments > Levels

This will bring up the Levels control menu.

Select the white eye-dropper icon, and click on the light-grey background image.

Next, experiment with the black, white and medium sliders.

In most cases, you'll be able to make the background white, the colors more intense, and the blacks black. Got it?

For further cleaning up, experiment with the Dodge and Burn tools to "bleach" out the white areas and "pump up" the shadows.

Comments

[Mark Pinto]

I have been using a macro I picked up, which is working well, especially when I am in a hurry. I sometimes find it is not flexible enough, where these steps will give a little more flexibility for creating clean sharp images. Thanks.

[Bruce Flye]

To clean drawings I've been using Whiteboard Photo by Pixid (http://www.polyvision.com/products/wbp_reviews.asp) I think it cost us about $100. Basically you load a photo, crop as needed and then "clean." It's fabulous for line work on white paper. If there are fields of color, such as large swatches of chalk shading or colored cards on a purple sticky wall, stay with Photoshop.