1.

To begin, start Photoshop CS by double clicking the desktop icon, or by using the start menu.

2.

When Photoshop CS has opened, use the Photoshop file browser to load the Eagle.psd image. (Remember that File->Browse or Shift + Ctrl + O will open the file browser.)

3.

Invoke the image size dialog by right clicking on the image canvas title bar and selecting Image Size from the menu, or by choosing Image -> Image Size from the Photoshop menu bar.

In the Image Size box, you can see that the Eagle picture is 424 pixels wide, by 640 pixels high. In the Document Settings area of the dialog box, you can see that at a resolution of 72 pixels per inch, the image would print at 5.89 inches wide by 8.89 inches long.

Make sure that the Resample Image checkbox is checked and that the re-sampling technique is Bicubic.

4.

Since 72 pixels per inch does not provide enough print quality, you will use Auto Resolution to increase the pixels per inch figure. Click the Auto button to display the Auto Resolution box.

Next, select the radio button labelled Best, and click the OK button to automatically adjust the dimensions and resolution of the image for a higher print quality.

5.

Now you can see the results of the resolution adjustments in the Image Size dialog box.

Notice that the pixel dimensions have been increased to 1566 by 2364, and that the resolution has been increased to 266 pixels per inch. Notice also that the print dimensions (document size) have remained the same at 5.89 inches by 8.89 inches. The increased pixels per inch value came via an increase in the pixel dimensions by re-sampling.

6.

Click the OK button in the Image Size dialog box to see the resized image.

When the dialog box disappears, enter 100 in the zoom field at the bottom left of the screen (status bar) to see the image at its new actual size.

Remember, you can control the portion of the image that is in view by dragging the red square on the Navigator palette.

7.

Examine the image closely, looking for artifacts caused by the re-sampling process. Look for jagged edges on lines of high contrast, and for blocky or banded areas.

Next, press the Ctrl + Z keys to undo the size change.

Examine the edges and detail of the image again. Can you notice a difference in clarity of detail, edge sharpness, or colour?

8.

Right click on the image title bar and again select Image Size from the menu.

At the bottom of the image size dialog box, clear the Resample Image checkbox.

Next, click the Auto button again to invoke the Auto resolution dialog, and set the image quality level to “Best”. Click OK in the Auto Resolution box to automatically adjust the image size.

Notice how the document (print) size is only 1.59 inches by 2.4 inches. This is because the image was not re-sampled. To get the same high quality print resolution, the size of the printed picture had to be reduced to increase the number of pixels per inch that will be printed. Click the OK button, and the image on your Photoshop screen will remain the same, because there has not been a change in the pixel dimensions (no re-sampling).

9.

Next, choose File->Print with Preview from the menu bar.

Here you can see the size of the image in relation to the size of the paper. This is an indication of how small the image must be to have a high level of print quality, without re-sampling the original image.

Once again, to print large high quality images, you should begin with a large image file, originally captured with high resolution. If you want to print this image now, click the Print button.

10.

Close Photoshop CS without saving any changes to the image.