Preview is the default image editor for your Mac. Even though it's shipped along with your Mac for free, but it's surprisingly useful for Mac users, especially for those who have upgraded to Mac OS X Leopard.

First, I will guide you to learn the very first and important technique of using Preview application, i.e. opening multiple images at once in one Preview window.

1. Opening Multiple Images at Once

Before you opened many images file with your iPhoto, think first. You will give heavy load to your Mac. It's better for you to open all of those images file with Preview application.

When you're going to open many images at once, don't forget to set your Preview Preferences (Command-Comma) to open all selected images in one window (if not, all images will be opened in separate windows).

And then, don't forget to open all of your images file with Preview by Control-Click on one of the selected images and choose Open With ▸ Preview. I know this won't be difficult for you.

2. Combining Multiple Images

Let's say you have hundreds of beautiful wallpapers (like mine) and you want to combine them to reduce the number of files required to show all of them. Assuming that you want to put sixteen images for every single page, you can do the following steps:

1. From Preview sidebar pane, select all images (Command-A)
2. Choose File ▸ Print Selected Images (Command-P)
3. Change the Layout to display Pages per Sheet: 16
4. Click on the PDF buttons on the left hand corner of the pane and choose Open PDF in Preview

Tip: Pay attention to the Layout settings shown on the screenshot above.

Then you will get your images combined, sixteen images per page, like what's shown on image below.

Tip: Don't use the option Images per page from Print Preferences Pane because it will combine your images without padding, i.e. the result won't be this nice.

3. Grab Applications' Icon

So, let's say I like the icon of Yahoo! Messenger. In order to move the icon along with the transparency to Preview pane, these steps will do:

1. Select your application (in this case, Yahoo! Messenger)
2. Control-Click on the icon and choose copy (or keystrokes Command-C)
3. Now change to Preview pane and go to File ▸ New from Clipboard
4. You've successfully get the icon!

Tip: Mac OS X Leopard default applications' icons are in larger dimension than other third party application (example as shown on screenshot below).

4a. Batch Rotate Images

To keep it short, let's say that you've loaded many images into your Preview display pane. If you want to rotate all of your images you can do:

1. Select all images on sidebar (keystrokes Command-A)
2. Choose Tools ▸ Rotate Left/Right and all images will be rotated
3. You can also use keystrokes Command-L or Command-R to rotate

Tip: You can select only several images (not all) to be rotated like the way you select files, i.e. using Command modifier key.

4b. Batch Resize Images

When you want to resize several of your images to certain dimension, you can do that easily with Preview application. First thing you need to do is selecting batch of images you want to resize from Preview sidebar pane. And then:

1. Choose Tools ▸ Adjust Size
2. Set the width, height and resolution for your batch of images then click OK
3. Confirm the changes by saving your batch of images: File ▸ Save All (keystrokes Option-Command-S)

5. Powerful Color Adjustment

This is a new cool feature for Mac OS X Leopard Preview application which you will have a pane to easily adjust your images' color attributes, such as Exposure, Brightness, etc. This pane can be activated by clicking on Tools ▸ Adjust Color (keystrokes Option-Command-C).

This is such a handy tool, for example you can do:

• Moving Sepia slider to the rightmost to get nice Sepia tone effect
• Adjusting Saturation slider to leftmost to get Grayscale image

6. Extract Shape from Background

On your Preview application toolbar, you will see a rectangle selection tool, click and hold that button. Then you will likely to see two (new) tools: Extract Shape Tools and Instant Alpha Tools. With combination of these two tools, you can extract a shape from its background, like shown on picture below.

You can see follow the step by step tutorial here: Preview Tutorial - Extract Shape.

7. Copy and Paste Icon/Portion of Image

Now, let's make use of selection tools to move portion of your image. We have three tools to draw selection here: Rectangular Selection, Elliptical Selection and Lasso Selection. You will get used to each of their functions once you try them.

Now let's assume that you've already draw your selection, then you can follow these steps:

1. Choose Edit ▸ Copy (keystrokes Command-C)
2. Move the focus on other pane (where you want to move your copied portion to) and click on the display pane
3. Use Edit ▸ Paste (keystrokes Command-V) and move around the copied image with mouse
4. Click anywhere on the display pane to confirm your changes then you're done dragging

If you've mastered the dragging technique, this can be used to Embed Icon into Stack Drawer.

8. Assign Color Profile

You can assign your image to one of the color profile provided inside your Preview application. By selecting the correct profile, you can produce a nice result for your printing. Choose Tools ▸ Assign Profile to assign a pre-defined profile to your image.

Shown below: comparison between Apple RGB (Left) and ProPhoto RGB (Right).

9. Add Annonations

Can you see tiny bar on the right hand corner of your Preview application pane? Option-Command-Click on it, you will see all available tools for your Preview application there. Drag the Annotate tool to your toolbar and play around with it. You will realize that it's really easy to use.

Example of oval and line annotation..

10. Enter Slideshow Mode

Now, I believe you've already known all useful techniques to enhance your images. The last thing you may want to do is presenting those images in front of your colleagues or maybe to your boss. You can use slideshow view for this (keystrokes Shift-Command-F).

Tip: In usual slideshow mode, you will get only one image displayed per slide. To get the result like above, click on the Index Sheet icon.

Are you satisfied with the result?

AWESOME tips for using Preview on the Mac