Computing for Beginners: Picture editing

By Colin Cartmell-Browne

LAST month we looked at the file management side of Picasa. This month we take a look at the editing functions. To give a detailed tutorial on every aspect of Picasa would be impossible, given the space available. Instead I’ll tell you how to access some of the key functions and give you just enough information for you to go and explore Picasa yourself. Just remember that it would be a good idea to backup your photographs first, just in a case something goes wrong!

Once Picasa has loaded just double click on the image you want to edit, to bring up the editing functions. You will be presented with this view. See Figure 1:

Figure 1

Figure 1

Common needed fixes tab – See Figure 2

Figure 1

Figure 2

Crop: This allows you to zoom in (or crop) the picture to remove unwanted parts of your image. Click crop and then either select from one of three preset crops or hold down the left mouse button and create a square/rectangle of the bit of photograph you want to keep.
Straighten: Ever taken a picture of a lighthouse or tower and thought afterwards that it looks ‘wonky’ ? This is the tool to fix that problem. Click ‘Straighten’ then move the slider left or right to get the desired effect.
Red Eye: automatically detects and removes red eyes- usually caused by the subject being too close to the flash when the photograph is taken.
Auto Colour, Auto Contrast & I’m Feeling Lucky- these functions are a one click deal for changing the depth of colour or contrast on your photographs.
Text: Allows captions to be added to your photograph including the ability to change font, text size and text colour etc.
Retouch: ‘Touch up’ a photo by removing unwanted marks or blemishes. Select ‘Retouch’ click the area you want to move a blemish from and then chose the area you want to clone from. Picasa will now ‘clone’ the colours from the second area onto the first. You can change the ‘brush’ size depending on the size of the blemish to be removed.

 

 

Finely Tuned colour and lighting fixes – See Figure 3

Figure 3

Figure 3

Fill Light & Highlights: These functions increased the ‘brightness’ of a photograph. Fill light increases the brightness over the entire photo, i.e. it brightens all the pixels. Highlights increase the brightness in select spots, those with bright pixels. Next to the Highlight slider is magic wand. Clicking this is a ‘one click fix’ for the lighting issues.
Shadows: Does the opposite of the Highlights function. It reduces the dark pixels and makes the shadows darker.
Colour Temperature: Sliding this bar to the left can make a photograph look ‘colder’. Sliding to the right can make it look ‘warmer’.
Neutral Colour Picker: Allows you to pick a neutral grey or white part of the photo and alters the photo accordingly.

The magic wand next to the Neutral Colour Picker is a ‘one click fix’ for colour issues with your photograph.
With both this and the Most Common Fixes tab there is a ‘Undo’ and ‘Redo’ button- which are pretty self explanatory!

A word of warning – if you change the colour of the photo and then save the photo the changes are often irreversible. Always work on a copy of an original photo in case of mistakes!

 

 

 

Fun & useful image processing

Figure 4

Figure 4

The final three tabs contain fun and useful image processing functions. (see Figure 4) Some, like the ‘Sepia’ and Black and White’ function are simple click once type fixes others you need to move a slider or play around with to get an interesting effect added to your photo.

On each tab is a graph and information. This is information from the camera including what settings were used. The colours on the graph help photographers improve their images, although I rarely use it.

Finally- these computing columns are written to aid you- what subjects would you like me to cover?

You can contact me via the Egremont 2Day email egremont2day@gmail.com or see Page 2 for contact details.