Introduction to Photoshop Altering photos 1 pixel at a time

Introduction to Photoshop

Altering photos 1 pixel at a time

What is a pixel?

-  Unit of measurement- Smallest piece of information in a picture- Sometimes referred to as a dot (DPI)   

Web resolution    

The resolution of photos on the Web is 72dpi (dots per inch)

There are 3 different file types most often used on the Web:- JPG- GIF- PNG

What is a GIF (Graphics Interchange Format)?- 8-bit graphic limited to 256 web colors or less.- Best used with graphics (not photos)- Can have transparent backgrounds- Can be animated (multiple frames)

What is a JPEG (Joint Photographic Experts Group)?- You can create images using all 16.7 million colors - An image that has been compressed for the Web, Low, Medium, High, Very High, Maximum.- Best used with photographs or other images using a wide spectrum of color- Can leave compression artifacts- This is the format you want to save photos for the Web- No difference between files saved as .jpg or .jpeg, although .jpg is more common.

What is a PNG (Portable Network Graphics Format)?- An option for newer browsers (IE)- Has better compression and uses millions of colors- Can have several transparent colors- Variations of transparency

Big >> small

Small >> big

Cropping photos

Cropping is decreasing the size of photo height, width and/or resolution. 

1) To crop to a specific height or width: Use the crop tool

Step 1 - Cropping photos

Decreasing the size of photo height, width and/or resolution

Cropping photo by size

1) To crop to a specific width: Use the crop tool

Cropping photos by shape

2) To crop to a specific shape use the rectangular selection tool:  Select the area you'd like to crop with the select tool and choose "Crop" from under the "Image" menu

Step 2 - Sharpening photos

Making things clearer

Sharpen photos

If photos aren't as crisp and clear as you'd like, try sharpening the photo. Filter > Sharpen > Sharpen OR Sharpen edgesNOTE: Don't do this too many times or it will distort your photo.

Color correcting photos

To do an overall color correct, go to Image > Adjustments > Levels > Auto

To manually manipulate colors, you can either use curves or color balance under the Image menu.

Step 3 - Saving photos

Saving for print and online

Saving for the Web

File >> Save for Web & devices  

JPG artifacts

Keep the proportion of the photoChanging the proportion of a photo alters the credibility

Uploading and sharing your photos in

- Create an account at https://picasaweb.google.com. Or log into your ASU e-mail, and then navigate to the URL and create a Picasa account that’s tied to your e-mail address.

- From the Home screen, click on the “upload” button at the top middle of the window.

- Type in a name for your album, and either drag photos directly from your computer into the window, or hit the “Select photos from your computer” button. You can select multiple photos at once by holding down the “Command” key.

- When you upload the photos, you’ll have the option to add captions by clicking “Add Caption” just below each photo.

Uploading and sharing your photos in

- Hit “OK” at the bottom-right of the window to create the album.

- Once you’ve created the album, you can access it by clicking on “My Photos”, and selecting the album you want.

- Once you’re in the album, click the “Slideshow” button in the upper left to preview what the photo story will look like.

- If you want to add more photos, simply click on “Add photos” when you’re inside the album.

- When you’re done with it, click on the “Share” button, and include that link in your social-media pitch.

Photo assignment continued...

- Crop your 5 photos to be 500 pixels by 350 pixels wide.

- Color correct and sharpen them.

- Upload them to a photo-sharing website.

- Use the tool for whichever website you choose to create a slideshow, with complete cutlines.

- Submit pitches with links to assignment via social media.