Basic image editing with GIMP on Ubuntu

GIMP is a free, open-source image editor that runs well on Ubuntu and handles everyday raster graphics without a paid subscription. It is useful for cropping family photos, tidying product shots for an Australian small business, preparing screenshots for a tutorial, or making artwork for community flyers. Its layer system may look intimidating at first, but the core tools are approachable once you understand the canvas, Toolbox, and Layers panel.

Ubuntu does not include GIMP by default in many installations. The quickest route is to open Terminal and install the desktop package with sudo apt update followed by sudo apt install gimp. Ubuntu Software may also offer a Snap version; either edition provides the familiar GIMP workspace, although this guide uses the commands shown above and the standard desktop package.

A reliable editing habit is to keep three kinds of files separate: the untouched source, the working GIMP image, and the finished copy you share. GIMP’s native XCF format preserves layers, masks, and text so you can return to an edit later. Export a PNG or JPEG only after the image looks right, rather than repeatedly overwriting the original photograph.

The workflow suits Australian users who edit outside major cities as well as those in Sydney, Melbourne, Brisbane, or Perth. Regional internet can be slower or inconsistent, so working from a local folder and exporting a final copy avoids interrupted uploads. Small businesses often use a mix of Canva, Adobe tools, and GIMP; for a café in Brisbane or a tradesperson preparing quotes in Adelaide, having a capable image editor available at no licence cost can be genuinely practical.

Install GIMP and open its workspace

Open Terminal from Activities, paste the update command, and wait for it to finish before installing GIMP. If your Ubuntu release or repository provides a newer release, the package manager will select it automatically. When installation completes, launch GIMP from the applications grid or run gimp in Terminal. The first opening can take a few seconds while fonts, brushes, and plug-ins are indexed.

The default interface contains a Toolbox on the left, a canvas in the centre, and dockable panels such as Layers, Brushes, and Undo History on the right. If those panels are missing, enable View > Single-Window Mode and check Windows > Dockable Dialogs. Keep the pointer, zoom, and layer panels visible while learning. Use + and - to zoom, hold Space to pan, and press Ctrl+Z whenever a change looks wrong.

Build a safe editing workspace

Create a project folder containing the source image, an XCF working file, and an exported subfolder. When you open a JPEG in GIMP, do not edit the copy on your camera, phone, or cloud drive as though it were the only version. Use Image > Duplicate for a separate working canvas, or duplicate the background layer from the Layers panel, then choose File > Save As and use an .xcf extension. XCF keeps editable components intact and is safer than flattening everything into a photo format.

Keep at least one additional copy on another drive or in a synced folder. That habit helps prevent data loss if a laptop fails, a sync conflicts, or an accidental save changes the wrong file. This is especially useful for people who move between a home office and a regional worksite. GIMP’s own Undo History is useful for mistakes within one session, but it is not a backup of a closed project.

Respect image rights and personal information as part of the technical workflow. Australia’s Copyright Act 1968 can protect photographs, logos, artwork, and published text, and creators may also have moral rights that are not transferred by assigning copyright. Get permission before reusing a client’s photo, and do not remove attribution or watermarks merely because the image is easy to download. If a business handles identifiable people’s information, check whether the Privacy Act 1988 and Australian Privacy Principles apply. Likewise, an edited advertisement still needs to comply with the Australian Consumer Law when it presents price, product, or performance claims.

Crop, rotate, and resize with control

Choose the Crop Tool from the Toolbox or press Shift+C, then drag a rectangle over the subject. The active crop area darkens the excluded portion, helping you judge the composition before committing. Check that heads, products, and important captions are not clipped. Press Enter to apply the crop, and use Undo if the frame was accidental. For a social post, enter the desired pixel width and height in the crop options and keep the chain linked so the aspect ratio stays fixed.

Rotation and flipping are separate from scaling. Use Image > Transform to rotate by a precise angle, then Image > Transform > Flip Horizontally or Vertically if the source was scanned in the wrong direction. For a resize, open Image > Scale Image and choose pixels, percentages, or a unit such as millimetres. Use the chain icon to lock the proportions; unlock it only when a deliberate distortion is required. For printing, remember that the image’s pixel dimensions and resolution metadata determine its physical size, so check both rather than relying on what appears on screen.

Adjust colour and sharpen details

Colour controls are under the Colors menu. Brightness-Contrast is a safe starting point for a dark phone photo, but small adjustments usually look more natural than extreme values. Curves gives finer control over highlights and shadows, while Hue-Saturation can strengthen a colour that feels muted. Watch the preview at 100 per cent zoom because GIMP’s fitting mode may conceal clipped highlights. If an adjustment is too strong, Ctrl+Z restores the previous state before you try a different approach.

For a slightly dull or hazy image, try Colors > Levels and move the black and white points inward rather than adding heavy saturation. Keep a copy of the original layer before broad changes, then lower the layer’s opacity to compare the result with the untouched pixels. When sharpening, use Filters > Enhance > Sharpen (Unsharp Mask) with a modest amount and radius. Zoom in on edges such as roof tiles, foliage, or lettering, since excessive sharpening creates halos and makes compressed camera noise obvious.

Retouch with selections and healing tools

Use a selection when the change should affect one defined area. The Rectangle Select and Ellipse Select tools suit a clear boundary, while Free Select follows a more irregular shape. Feather the edge slightly to avoid a hard, pasted-looking join, then use the foreground colour, paint, or healing tools inside the selection. The marching outline lets you confirm that stray objects have not been included.

For dust spots, power lines, or a small distraction, use the Heal tool or a small brush with the Clone tool. Sample from nearby clean texture and work at a modest zoom; repeated scrubbing can blur the repair. The Smart Remove tool can also remove small unwanted items in newer GIMP versions, but it is less predictable around complex textures. Major changes to faces, documents, or evidence should not be presented as unedited photographs, and a retouched product photo should still match the item the seller is actually offering.

Add text and export the right file

Select the Text tool, click on the canvas, and type. GIMP creates a text layer that remains editable until you flatten or rasterise the image. Choose a clean Ubuntu system font, adjust the size on the canvas, and use the Text tool’s alignment controls for multiple lines. Place text on a separate layer so its contrast can be checked against the background. A subtle shadow or outline can improve legibility on busy photographs, although a translucent colour band is often simpler for Australian community posters and market-stall signs.

Use File > Export As for the final image, and select PNG when you need sharp edges, transparency, or screenshots. JPEG is more compact for ordinary photographs, but its lossy compression can create artefacts around text and sharp lines. In the export dialog, check the quality preview and avoid repeated saves, which can degrade the file further. Keep the XCF as the editable master, and name exports with useful details such as brisbane-cafe-menu.png rather than a generic final2.png.

Before sharing, remove hidden layers, personal notes, or location metadata if they are not intended for the audience. Check the exported copy at normal viewing size and with the file manager’s thumbnail; a convincing canvas preview can still hide a shifted crop. For a website, export a copy at the size the page actually requests. For email or social media, follow the platform’s dimensions, then inspect the result on both a desktop monitor and a phone screen.

Print, share, and finish the workflow

For a sharp A4 print, an effective resolution of 300 pixels per inch is a practical target. A full A4 page at that resolution is about 2480 by 3508 pixels, though margins and the printer’s printable area may require a smaller image. Check the dimensions under Image > Print Size and preview on paper before using a large batch. If an office printer is shared through a Linux print queue, this Ubuntu print server setup guide explains the CUPS workflow for Ubuntu.

Sharing a finished image starts with choosing the recipient and purpose. Compress a large PNG for email, upload a version sized for a website or social platform, and retain the full-resolution master for future use. In a workplace, follow the organisation’s retention rules and avoid copying client images to personal cloud accounts. For commercial material, confirm that logos, fonts, stock photos, and recognisable locations may be used, and keep a record of permissions so the final campaign remains defensible under Australian consumer and copyright rules.

This first session can cover one image: open an original photo in GIMP, duplicate its background layer, crop it to a 4:5 frame, and save the result as an XCF working file beside the source.