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Are your PowerPoint files over 10M in size? Maybe the problem is the size of the images within the files. The tips below can help you use an image editing program like Photoshop or other image-editing program to reduce file size. Believe it or not you may be able to convert an 12 MB PowerPoint file to only 1 M just by reducing the file sizes before importing them into PowerPoint.

Photoshop vs. Other Programs

Photoshop is the industry standard and is found on all public lab machines and is available for purchase from the Computer Store for a discount; another is Fireworks. Other options include: Paint (free on Windows), Preview (free on Mac), Photoshop Elements (a lower-cost version of Photoshop with powerful features), Paint.Net (Windows), Gimp (freeware for Windows and Mac/X11), iPhoto (on iLife) (Mac) and others.

The Tips

1. Always work with a copy of the original photo.

If something goes wrong in Photoshop, it’s a good idea to have a back-up copy you can start over with.

2. Crop your photos.

That is, select the part of the photo that’s the most important and discard the rest.

  • In Photoshop and Paint the crop tool icon of crop tool is on the main tool bar. Select the tool, adjust the rectangle to enclose the part of the image you want to keep then press the Enter/Return key.
  • In Paint, use the mouse to select the portion to keep, then go to the Image menu, then Crop (Image » Crop).
  • In Preview, use the mouse to select the portion to keep, then go to the Tools » Crop.

3. Shrink your photo before you import it into Photoshop.

That is, resize a large image in Photoshop first instead of in PowerPoint. Resizing an image in Photoshop reduces the file size. If you resize in Powerpoint, the entire file is embedded within Powerpoint even if the display size is reduced.

  • In Photoshop, the tool to adjust photo size is under the Image menu (Image » Image Size):
    Note: If small image appears jagged, undo the change and then go to Image » Mode » RGB Color then return to the Image Size window.
  • In Paint, the tool is under Image » Resize
  • In Preview, the tool is under Tool » Adjust Size

4. Convert to GIF or JPG Format

Use JPG (JPEG) format for photos and gradients and GIF for simple illustrations.

  • In Photoshop:
    • For JPEG, go to File » Save As and select JPEG in the file format menu. Set quality option to 5.
    • For GIF, go to File » Save for Web. The fewer colors used the smaller the file (preview for best view).
  • In Paint, go to File » Save As and select either GIF or JPEG.
  • In Preview, go to File » Save As and select either GIF or JPEG. If you select JPEG, set the slider to Medium quality.

Note on PNGs: PNG is another format used on the Web, but some PNG files are better optimized than others. Generally speaking, PNGs exported from a package like Illustrator are smaller than those exported from Microsoft Office, Photoshop or captured on a Mac screen.


The three tips above should shrink a lot of file sizes for your images, but if you still have problems consider checking the following:

  1. Check DPI (dots per inch) or resolution. It should be 72 dpi for the Web print and no more than 150 if you absolutely need an image to be print quality.

    • In Photoshop you can change resolution under Image » Image Size. Make sure the size of the image does not get larger.
    • This cannot be easily done in Paint.
    • In Preview, you can change resolution under Image » Resize
  2. Convert black and white images to grayscale. This discards redundant color information and keeps lightness/darkness information only.
    • In Photoshop, this can be done by selecting Mode » Grayscale.
    • In Preview, this can be done by selecting Tools » Adjust Color. Move the Saturation slider to black and white.
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