All image editors provide a workspace with menu bars and toolbars for accessing all the adjustments. Although their layout may be a little different and some tools can be grouped differently in different sub-menus, in essence most of the tools will do similar things.
More powerful programs will provide more tools than simpler programs like Google Photos. Entry-level software is more likely to automate a lot of functions, which can restrict what you do with some tools. For this reason, we are using the more powerful applications for our demonstrations.
The lens correction, HDR adjustments and the Photomerge functions are circled in red in this screen grab showing Photoshop’s File sub-menu.
The Menu Bar
The menu bar contains settings that enable you to open image files, change the size and orientation of images, alter colour, contrast and saturation and work with layers and selections. It also provides access to both special effects filters and sharpening and noise-reduction tools (which are grouped together in the Filters sub-menu).
Selecting a particular menu item is straightforward; you just click on the item in the list and move your pointing device onto the item or tool you wish to use. In some cases you will need to click across to a sub-menu to choose a specific tool.
Unlike menu items, tools are usedӬ to work directly on the image itself. They require you to use a pointing and/or selection device to define the area you will work on and apply the adjustment.
The File sub-menu generally contains the functions for saving images, either by over-writing the original copy or savingӬit as an additional copy. In Photoshop, it also contains a useful Automate section that contains lens corrections, HDR (high dynamic range) adjustments and the Photomerge functions for combining images to produce panoramas.
Screen grabs of the editing workspaces of Photoshop (top) and GIMP (below), showing their similarities and differences. The Toolbox in GIMP is only revealed when you click on an arrow in the Palette bar, whereas it is visible by default in Photoshop. Note the similarities in the functions both editors provide.
Essential Tools
Tools can be divided into five basic types: selection tools, painting and drawing tools, enhancement tools, navigation tools and text tools.
The editing sub-menus in the menu bar of GIMP
1. Selection tools enable you to select specific areas in an image.”¨They include lasso and marquee tools, quick selection brushes and ‘magic wand’ tools. The screen grabs below show the individual tools within each group in Photoshop.
The marquee tool is used for selecting geometric shapes.
The lasso tool lets you draw around irregular shapes.
2. Painting and drawing tools simulate artists’ tools for creating images from scratch. They include brushes, erasers, pencils, paint buckets and gradient tools. Brushes, erasers and pencils are customisable; you can adjust their sizes, edge softness (or hardness) and in many cases the shape and angle of the tip of brushes to provide different end results and levels of control. Each of these tools acts on a small, selected area of the image.
The paint bucket and gradient tools act on the entire image. The paint bucket tool floods the frame with a selected colour and tone, while the gradient tool is used to selectively darken or colourise one side of the frame (usually the top, where it is applied mainly to the sky).
Both these tools can be adjustedӬ to control the depth of the effect they produce. You can use the Edit>Fade slider to control the intensity of the effect after it has been applied.
Fading the gradient tool to produce a more natural-looking effect (lower image).
3. Enhancement tools include tools like clone stamps and healing brushes, which are used primarily to correct blemishes. The clone stamp lets you ‘paint over’ a blemish with a selected (unblemished) area in the image, while the healing brush can sample the area around the blemish and use it to create a seamless patch that makes the blemish disappear.
Dodging and burning tools are similar to those used in a traditional darkroom. The dodging tool is used to lighten a selected area, while the burning tool can darken it. Both tools let you select which tonal level to work on: highlights, mid-tones or shadows. You can also adjust the size and hardness of the brush as well as its intensity.
Other tools in this category include brushes for sharpening, blurring and smudging as well as red-eye removal tools, which provide a one-touch fix for correcting the red eyes that often occur in flash photos when the flash is close to the camera lens axis.
4. Navigation tools help you to find your way around an image that has been enlarged beyond the confines of the workspace. The main tool is indicatedӬby a hand icon. Clicking on this icon lets you move an enlarged image around the window frame. Slide bars that appear along the side and lower edge of the workspace when an image is enlarged can fulfil a similar objective.
5. Text tools let you add text to an image. Most editors let you orient the text vertically or horizontally and some provide curved paths on which text can be aligned. A wide variety of font styles and type sizes is usually available.
What if you make a mistake?
Sometimes you find the adjustment you just made didn’t achieve the desired end result. That shouldn’t be a problem as almost all editors allow you to undo changes and some provide a wide range of options for ‘fading’ the intensity of adjustments.
If you simply want to reduce the impact of the adjustment without totally removing it, clicking on Fade in the Edit sub-menu opens a slider that lets you move between 100% and no adjustment. This gives users a high degree of control over the strength of adjustments.
The History palette allows you to see every editing step you’ve made. Reversing changes is”¨as simple as selecting the step before the point where you want to begin again. More sophisticated applications also provide a Revert button (File>Revert) that lets you discard all adjustments made to an image and return to the original image as it was first opened.”¨this function takes you back to the saved original (or copy) you started with.
The History palette tracks each step in the editing process and makes it easy to return to any point and start again.
Some editing programs limit the number of times you can undo edits; others let users set their own limits, while the most sophisticated editors provide ‘unlimited’ undo capabilities. As each editing step has to be stored in the ‘scratch disk’ memory until the editing process has been completed and the end result is saved, setting a limit to the amount of undo/redo will allow edits to be processed faster and save memory on the scratch disk.
The dialogue box in GIMP that lets users set the number of Undo steps and the amount of scratch memory allocated to the Undo function.
Useful links
www.bit.ly/edit-and-share-photos
www.bit.ly/best-photo-software
www.bit.ly/low-cost-photo-software
Excerpt from Photo Editing Pocket Guide
