Editing B&W Line Drawings

This page will walk you through the process of editing a black and white line drawing using Photoshop.

The following procedures will be covered: 1.) Rotating the image, 2.) Cropping the image, 3.) Increasing the contrast, 4.)  Increasing the Threshold to blacken the lines, and 5.) Removing unwanted lines using the Paint tool.

The first step is to open Photoshop.

Then open your image file. Note: It is recommended that you save the file as a jpg or gif file when you scan it. It is also recommended that your name the file so that it describes the content of the image.

The image below could use some editing. The image should first be rotated so it is horizontal on the screen.

You can alter the rotation by selecting Image Rotation under the Image menu. The Arbitrary selection will allow you to make adjustments in specific degrees.  

Determining the angle requires a little trial and error. The image above probably needs to be rotated about 10 degrees in the clockwise (CW) direction. 


Your image may need to be cropped. The image below needs to cropped to include the area within the orange rectangle.


In Photoshop select the Rectangular Marquee tool.

Make a rectangle around the area to be cropped by picking two points at opposite corners.

From the Image menu select Crop.

The cropped image is shown below.

You can see that there are areas of gray in the background. To eliminate this you can increase the contrast.

Adjust the contrast level to 100.

The image with increased contrast is shown below. The background is now white. You can increase the contrast more than one time. 

You can see that the line work is a little gray too. To increase the blackness of the lines, you can adjust the Threshold of the image.

Hold your left mouse button down and slide the arrow to the right to increase the blackness of the line work.

To erase unwanted line work you can use the erase tool, but the preferred method is to paint using the color of the background. 1.) Click on the eyedropper tool. 2.) Then click somewhere in the white area of the screen.

The new sampled color should appear at the bottom left corner of the screen.

Use the Paint tool to eliminate unwanted line work.


Click on the arrow to change the settings for the brush as necessary.

The finished image is shown below.