Quick links to procedures on this page:
Portable Network Graphics (PNG)
The Portable Network Graphics (PNG) file format is an excellent file format for lossless, portable, and well-compressed storage of bitmaps. It takes up a minimum amount of disk space and can be easily read and exchanged between computers. The Portable Network Graphics format provides a replacement for the GIF format and can also replace many common uses of the TIFF format.
The Portable Network Graphics format is designed to work well in online viewing, such as on the Web, and it’s fully streamable with a progressive display option. Some Web browsers do not support all formatting and features. You can export images to the Portable Network Graphics file format if you want to use transparent backgrounds, image interlacing, image maps, or animation in your Web pages.
Exporting graphics to the Portable Network Graphics format converts them to bitmaps that can be used in desktop publishing programs and Microsoft Office applications. You can also edit Portable Network Graphics in image-editing programs such as Corel PHOTO-PAINT and Adobe Photoshop.
You can also save images to the GIF and JPEG formats to use on the Internet. If you want to publish an image to the Web but are not sure which format to use, see “Choosing a Web-compatible file format.”
To import a Portable Network Graphics file |  |
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The File
 Import command lets you place the file as an object in the active image. If you want to open a PNG file as an image, click File Open. |
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(Windows Vista) Choose PNG – Portable Network Graphics (*.png) from the list box next to the File name box.
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You can also
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Resample a graphic while importing
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For more information, see “To resample an image while importing.”
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Crop a graphic while importing
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For more information, see “To crop an image while importing.”
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To export a Portable Network Graphics file | |
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Image color — makes the color you click on the Color Palette transparent
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If an image contains objects, an alert warns you that objects will be merged with the background.
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If you enable the Masked area option, you can enable the Invert mask check box to make the selected area transparent instead of the masked area.
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You can specify the transparent color by using the Eyedropper tool to click a color in the Original window or by moving the Index slider.
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You can zoom in to get a closer look at the image by clicking in the Original window. You can zoom out by right-clicking in the Original window.
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Portable Network Graphics (PNG) technical notes | |
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You can import Portable Networks Graphics (PNG) files from 1-bit black and white to 24-bit color; 48-bit color is not supported.
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Masks and indexed-color, grayscale, and true color images are supported. Masks, however, are not saved in 1-bit black-and-white or 8-bit paletted files.
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LZ77 compression is supported, and the maximum image size is 30,000 × 30,000 pixels. Sample depths range from 1 to 16 bits.
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