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Image Editing Software

Last updated: 21 January 2009
Published in: Digitising analogue media | Creating new digital media
Tags: gimp | image editing | photoshop | software

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Summary

Once you have created a digital image, you will nearly always need to undertake some form of image editing before it is ready for archiving or delivery. This paper looks at what you will need to consider when choosing the right software for your needs.

Introduction

There is a wide range of image editing software available, covering everything from simple image optimisation to complete image creation.

Understandably, the cost of the different programs on offer varies enormously. There are many factors to consider when choosing a program, but the final choice should ultimately be based on its suitability to the task and the available budget.

This paper highlights the main considerations to take into account, and details the various features and functions to look out for. It then looks at a selection of the programs currently available.

Considerations when choosing image editing software

Basic considerations such as cost, hardware requirements and usability will need to be looked at, along with a careful evaluation of the specific features and functionality on offer. It is important to be aware that some software is written to handle specific functions only, or may be a plug-in or add-on that requires another program to run.

Cost - In addition to the cost of the application itself, which can range from nothing (for freeware) to several thousand pounds (depending on the number of licenses required), remember to budget for: future upgrades; training costs and/or time to become familiar with the package; additional hardware requirements. Some software publishers offer reduced licence fees to educational establishments.
Hardware Requirements - Software publishers provide details of the minimum system/hardware requirements (Platform, Operating System, Processor, RAM, Hard-disk space, and Display) needed for running their products. These are often accompanied by recommended or suggested requirements, and it is always wise to make sure your system matches these recommendations rather than the minimum: the minimum might mean the program runs, but it is unlikely to perform to its full capability.
Usability - It is always a good idea to try out software before purchasing it. It is usually possible to download a demo or evaluation version from the company’s Web site and then ascertain: How easy is it to use? How good are the Help files? Is a manual provided? Does the software publisher offer any technical support or online training? Are any third party guides available? Are there any online user forums or newsgroups? Are training courses available locally? Will the project be able to find staff with the necessary skills?
Functionality - Some of the features likely to be of most use to digital archives are listed below. It is worth remembering that some applications offer a range of features that are mainly aimed at designers and illustrators such as creative filters and special effects, many of which will be surplus to your requirements, but might be of use if you will be involved in producing Web graphics (buttons, navigation bars, etc.) from your images.
- File format support - will it import and export the image file formats you will be using? If you have a collection of images in an unusual format, check that the program supports it. Does the application have its own file format (or ‘native’ format, e.g. Paint Shop Pro’s .PSP or Photoshop’s .PSD)? An application’s native file format may support additional program features such as layer, mask and colour information. This is the sort of information that may be lost when saving to other formats, so it is good practice to save to the native format (it is usually the program’s default format) when work is ongoing, and to save to a standard file format (e.g. TIFF, JPEG) only once work has been complete. Always keep an unadulterated version of the image as a master copy, and if possible a native file format version of the adjusted image, together with the delivery versions - see File Formats and Compression for more information on file formats.
- Image optimisation tools - colour adjustment, auto levels, brightness/contrast, hue/saturation, sharpen, re-size, crop, rotate, flip
- Colour depth or bit depth - this is the number of distinct colours that can be edited by the image editing program. A higher bit depth provides a greater range of colours or tones of grey. Most image editing programs offer 8bits/channel as a standard. More powerful applications offer the ability to edit in the more colour rich 16bits/channel space. If a scanner or digital camera captures data at 16bits but is imported into an image optimisation program, which edits in 8bits then valuable data may be sacrificed.
- Native RAW file support - many digital cameras now offer their own native or RAW file format. A RAW file unlike the more familiar TIFF and JPEG formats does not receive any ‘in camera’ processing and is therefore a more faithful representation of the photographed object. It often contains a higher colour bit depth than its TIFF and JPEG equivalents. The RAW file is the digital ‘original’ and is normally archived unedited to avoid sacrificing the image’s integrity. The RAW data has to be converted into an editable format on the computer. Any optimisation should be applied to surrogate files. Most cameras offering native RAW capture are supplied with simple file conversion applications but these rarely offer the functionality of a true image-editing program. Some image editing programs now offer RAW file support.
- EXIF (Exchangeable Image File Format) - most digital cameras produce EXIF data. This data is embedded invisibly in the image file and can be exchanged between capture devices and compatible applications. The content of the EXIF data can vary between manufacturers and the specification level of the camera but might include: camera exposure settings, lighting conditions, date and time, photographer’s name, and location (via GPS). Some applications and optimisation processes may remove EXIF data.
- Image repair tools - clone/retouch, dodge/burn, colour correction
- Colour management support
- Multiple ‘undo’ levels/history palette
- Batch processing/macro facilities for repeat operations
- Text tool - useful if you need to overlay images with text
- Ability to save workspace settings so work can pick up where it was left off
- Built-in image management or file browser
- Layers, Masks, Paths and Channels can be used to control work on the image
- Web optimisation - useful aid for creating surrogate files for delivery to the Web, allowing you to adjust the size/quality ratio and preview a range of compression levels
- Watermarking - option to embed images with digital watermark

If the application does not handle some of the operations you require, you will need to consider if there is an add-on or plug-in available that can undertake the task, or whether it would be better to purchase another program.

A selection of image editing applications

Image editing applications are evolving rapidly, new features and updates for new camera formats are added regularly. For a full list of the available features the best place for current information is the publishers website. Below is a list of some of the most popular image editing applications with links to their web pages and approximate prices. The list also details the operating systems they support Mac, PC and Linux. Some image editing applications are hosted online and are independent of the users operating system. The list is arranged by price with the most expensive applications at the top.