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Then install Photoshop, start up it. Photoshop 7.0 is also a very good version, the usages of Photoshop 7.0 and Photoshop CS5 in this concise tutorial are same. Open a picture with Photoshop CS5, as below:
The screen resolution of iPhone is 320 X 480, We need to change or cut the size of pictures.
Change the size of picture. Select the menu bar "Image - Image Size...", as below:
Make sure "Constrain Image" is selected, as the red circle below. Input a value of Width or Height, as below:
Then press C key of keyboard, or click the "Crop Tool", as below:
Then drag the mouse, press Enter key, the picture will be cropped.
Crop the picture with the menu. Select the menu bar "Image - Canvas Size...", as below:
The unit select pixels, input a proper value of Width or Height, as below:
The effect is below:
Export the picture. Select the menu bar "File - Save for Web & Devices...", or press Alt+Shift+Ctrl+S, as below:
Please note: if the photo is more than 256 colors, you should select JPEG, "Preset" select "JPEG High", and Quality is 60, this quality is good enough. Usually our eyes can't differentiate quality 60, or quality 80, or quality 100 of JPG format. As below:
Last, the size of picture is 320 X 480, then transmit the picture to your iPhone. This picture below was taken in an apparel marketplace in Shenzhen city of China.