editing images for powerpoint using photoshop scanning for powerpoint Powerpoint help - scanning and optimising images

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We are experienced and highly skilled at scanning and optimising images for use in powerpoint - the images will always display quickly, can have areas of transparency (they don't have to be square!), and are guaranteed to look at least as good as the original. Composite images and retouching are no problem. Please contact us if you require this service.

Altenatively if you've got a scanner and some decent image editing software here's a brief overview of how to get the best from your images if you want to do it yourself

Your first consideration:

The resolution of the presentation laptop or projector

Data projectors are generally 800x600 pixel devices, some are now 1024x768, earlier models were only 640x480 - you need to know.

If it's for a laptop display the same applies - if you're not sure then 'right-click' on the desktop, select [properties], [settings] and see what it says about screen area. While you're there make sure that 'colours' is set to 'true color(24 bit)'

Your second consideration:

How much of the screen is this image going to occupy ?

Why is this important?

The computer can only display as many pixels as the resolution supports - if your scan is any bigger than this it will contain data that does not display. This will make the file size larger and slow down the presentation for NO visual improvement!

Conversely an image that is smaller than you wish to display will 'pixelate' (more than one pixel of your display will be used for each pixel of the image giving a blocky appearance)

Assuming an 800x600 display: no image should have a final size greater than either 800 pixels wide or 600 pixels high. A logo that will be placed at the bottom of a slide may only need to be 150 pixels wide. Bear all this in mind before you start...

Scanning

Now you know what size image you need (approximately) you can start scanning.

Your initial scan should be around 4x larger than the final image - generally 'the bigger the better'

Why?

This gives you some extra data to play with...

When you optimise the image (particularly when getting rid of blemishes, scratches etc) the additional pixels allow much more subtle editing.

The image is in Photoshop - what now?

1. Throw away anything you don't need - use the crop tool to trim any excess area that you scanned

2. Levels: sort out the light and dark. This is normally the single biggest improvement to any image. Try 'autolevels' first (under Image, Adjust, Auto Levels, or Shift+Ctrl+L) If you don't like the result click Edit, Undo or Ctrl+Z and then do it by hand Go to Image, Adjust, Levels, or Ctrl+L and move the three little sliders around under the histogram. This is a purely subjective operation but generally you want the blacks black, the whites white and then shift the bit in the middle until it's as good as it gets...

3. Colour balance: if the colours need general adjustment (particularly when you're scanning transparencies) select Image, Adjust, Colour Balance, or Ctrl+B and add or subtract until it looks better

4. Dust and scratches: sort these out using a combination of the rubber stamp tool and the dust and scratches filter. Rubber stamp to copy good areas over bad and the filter for areas without great detail (sky, solid colour etc)

It looks pretty good - what next?

1. Size: it IS important.

Now resize your image to its final size (under Image, Image Size) which you determined earlier - make sure that 'Constrain proportions' is on and that dimensions are in pixels

2. View the image at 100% magnification - are you happy with it?

Happy? Go to Saving

Unhappy? Start again from scratch - either re-scan or undo your edits back to the original (use Alt+Ctrl+Z) or go to the history window and step backwards

It's OK but...

Here's some more options

1. You can further tweak the levels, colour balance and maybe look at the brightness/contrast option under Image, Adjust

2. Try sharpening the image (Filter, Sharpen, Sharpen) - this almost always helps

3. Occasionally a slight softening of the image can help (Filter, Blur and then try a few options)

Saving

Once you're happy with your image it's time to save - but what format? Photoshop can save many different file types and PowerPoint can import most of them - how do you choose?

Your only considerations are size and speed. File size is determined by the number of pixels, whether or not the file format uses any form of compression and the amount of information stored for each pixel.

1. You've already sorted out the required number of pixels.

2. Compression: BMP file types apply no compression and are consequently relatively large. However since there is no compression, no time for decompression is required. BMP supports 24bit and 8bit colour depth - more on this later... GIF and JPG files types both compress the file size but in different ways. JPG compresses a file by throwing away information and you can select the degree of 'lossy' compression to apply. This makes the saved file considerably smaller but you need to be careful that you don't over compress and lose image quality. You also need to be aware with JPG that any subsequent save of the image will throw away more data and further degrade the image. GIF is a non-lossy compression but only supports a colour depth of 256 colours (or 8bit)

3. The amount of information stored: When you scan an image the basic format allows each pixel to be any of millions of colours (24bit) and this facility results in the truest reproduction of an image - it also requires a lot of data to be stored in the file. Files of this type can be saved as BMP or JPG. Alternatively you can reduce the amount of data stored to just 256 potential colours per pixel (do this with Image, Mode, Indexed colour - the options chosen should be Adaptive palette, 8bits/pixel, Diffusion dither). This works best on images that do not contain a great range of colour to begin with and is at its worst with any sort of graduation - experiment and simply undo the operation if you don't like the result. These images should be saved as BMP (selecting the 8bit option) or GIF.

We hope this helps - if you're having problems or simply don't have the time then remember that we're here to help.

 

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