The eyedropper tool is really comes in handy if you do a lot of work with image colour, especially if you work with precise colour values

 

 

The Eyedropper tool is grouped in the toolbox with the colour sampler tool, and the measure tool.

 

The Eyedropper tool lets you copy an exact colour from your image, and assign it as the foreground colour. If you have a digital image open in Photoshop CS, choose the eyedropper tool from the toolbox, and then click on a spot in your image. The colour of the spot you click on will become the foreground colour, letting you match the particular colour that you clicked on exactly.

 

When you choose the Eyedropper tool, you will see a Sample size drop list available in the options bar. If you display this list by clicking its arrow, you will see the following options for the eyedropper.

 

Point Sample	Will reproduce the colour value of the particular point (pixel) you click on.
3 by 3 Average	Will produce the colour value based on an average of 9 pixels. (a box of 3 pixels by 3 pixels around the point where you click)
5 by 5 Average	This option will produce a colour value based on a five by five box around the point you click. (this will be an average of the colour values for 25 pixels)

 

The 3 by 3 sample setting is often used for the eyedropper tool as this produces a precise, but representative colour match to the area you click on.

 

If you select the eyedropper tool and right click on an image, you will see a menu with the same three sampling options just discussed. In addition, at the bottom of the menu, you will see a Copy Colour as HTML option. You can use this option to copy the colour value as a hexadecimal number, which can then be pasted in html form in a document.

 

Here is an example of what would be pasted after copying a colour value with this option.

 

COLOUR="#AAAEB4"

 

In the context of an html command, it might look like this.

 

<FONT COLOUR="#AAAEB4"> Here is some text </FONT>

 

An interesting variation on the eyedropper tool is the colour sampler tool. With the colour sampler, you can place points on an image, and watch how adjustments to the image affect the points. Both the current values and the previous values for the points will be shown in the Info palette.

 

To use the colour sampler, first select it from the toolbox.

 

 

With the colour sampler tool selected, click on your image and you will see small circles with bars placed on your image. These markers indicate the spots in the image that will be sampled. You can place a maximum of four sample markers on your image that will be used to provide colour values as you modify the image. The original colour values for the markers along with the current colour values are displayed in the info palette. 

 

 

 

In this image, you can see four numbered sample markers on the picture, and four corresponding data sets in the info palette. As you are adjusting the colour of the image the current colour values will be displayed along side the original values. Once the image colour has been changed, only the latest colour values will be shown