Pixel Love

When it comes to photo retouching and image editing, Gimp is probably the most popular choice among Linux users. After all, it's a mature and powerful application available in the software repositories of many Linux distributions. You can find plenty of Gimp tutorials on the web, and due to the application's popularity, finding answers to your Gimp-related questions is relatively easy. Better still, Gimp is free in every sense of the word.

So, why then would you opt for something like Pixeluvo [1], a closed-source image and photo editing tool that costs money? For a number of reasons, actually. Gimp's interface is an acquired taste with its fair share of shortcomings (e.g., take a look at how the save and export features work). The application is loaded with features, and as such, it's not the easiest tool to master. And in most cases, you won't even need all the functionality Gimp has to offer. In short, if you are looking for an image editing application that offers just the right amount of functionality wrapped into a polished and user-friendly interface, then Pixeluvo is worth the money.

Getting Started with Pixeluvo

The Linux version of Pixeluvo is available as DEB and RPM packages for the 32-bit and 64-bit platforms. Download the appropriate package, and install it using the default package manager. To do this on Ubuntu and its derivatives, run the sudo dpkg -i pixeluvo_x.x.x._xxx.deb command.

To start working on an existing image, choose File | Open and select the desired file. You can also open an image or a photo by dragging it onto Pixeluvo's working area. Additionally, you can push images from other applications to Pixeluvo via the Open With context menu command.

Pixeluvo puts essential tools at your fingertips and neatly tucks the rest under various menus. As a result, the application features an unobtrusive interface that makes it easy to perform basic actions (Figure 1). The main toolbar on the left side of the main window gives you access to standard tools such as Crop, Straighten, Red Eye Removal, Dodge/Burn, and others. The palette in the upper-right corner displays a thumbnail of the currently opened image, while the slider underneath it can be used to zoom in and out (you can also do this using the mouse scroll wheel while holding down the Ctrl key). When you zoom in on the image, drag a rectangle area in the palette to quickly move around it. Hover the mouse over the palette, and you can use the buttons in the sliding drawer to switch between the thumbnail, histogram, and info views.

Figure 1: Pixeluvo features an unobtrusive interface.

The toolbar gives you access to several advanced yet easy-to-use tools. The Spot Heal tool, for example, lets you effortlessly remove specks and small blemishes on the image. Select the tool, point the mouse to the spot you want to remove, draw over it while holding down the right mouse button, and watch the spot magically disappear. Although the Spot Heal feature can be useful for fixing small blemishes, the Clone tool is suitable for removing large unwanted objects by painting them out using other parts of the image. Select an area of the image to clone by holding down the Alt key and clicking at the desired position. Then use the mouse to paint out the specific part of the image.

Magic Wand can come in rather useful when you need to quickly select regions of similar color. Click and hold down the right mouse button to start the selection, and then drag the mouse to specify the color matching tolerance (i.e., the size of the selection). Click on the appropriate icon in the options bar to extend the current selection or subtract from it (or use the Shift and Alt keys while making a selection).

In addition to an assortment of color adjustment tools, Pixeluvo features a handful of ready-made filters that let you quickly apply a specific effect to the image. Choose Color | Quick Color (or press Ctrl+R), and click on the desired filter. Use the Blend and Vignette slider to adjust the effect's strength and vignetting, and then press OK to apply the filter. The options under the Effects menu give you access to various effects: from Tilt-Shift and Local Contrast to Film Grain and Light Leaks.

Although some effects are more useful than others, there are a couple of entries in the list that can come in handy in many situations. The Soften Skin effect, for example, offers an easy way to make portraits more pleasing, whereas the Reduce Noise, Sharpen, Boost Detail, and Enhance Clarity effects can improve the overall image quality with a minimum of effort. Need to convert a photo to black and white or duotone? Pixeluvo has several ready-made filters for that. Choose Color | Monochrome, pick the filter you like in the Monochrome palette, adjust the Blend and Vignette parameters if needed, and hit OK (Figure 2).

Figure 2: The Quick Color feature offers a collection of ready-made filters.

If you find the default monochrome filter selection limited, the Threshold tool gives you more control over black-and-white conversion. This tool converts an image to black and white based on the brightness of each pixel. The threshold value controls which pixels are converted to black and which are converted to white. Pixels that are brighter than the threshold value become white, while all other pixels become black.

Several other creature comforts can help you to get good results with a minimum of effort. As the name suggests, the Replace Color tool can be used to easily replace a color in the image with another color with different hue, saturation, and lightness properties (Figure 3). Although the cross-process effect has become a cliché, when used sparingly it can liven up otherwise dull images. And, Pixeluvo's Cross Process tool lets you apply the effect with consummate ease. Photo Filter is another handy tool that simulates various color filters. It can be used to remove color casts or make the image warmer or cooler. Used creatively, this tool can also help to produce interesting effects.

Figure 3: Creature comforts like the Replace Color tool simplify many image editing actions.

Pixeluvo also offers a comprehensive set of color adjustment tools, including Curves and Levels as well as tools for adjusting saturation, brightness, contrast, etc. (Figure 4). All these tools follow the established paradigm, so if you understand their basic operation principles, you won't have trouble using these tools in Pixeluvo.

Figure 4: The application includes standard tools for curve and level adjustments.

To make the image editing process more efficient, Pixeluvo provides extensive support for keyboard shortcuts, and practically all tools and features can be activated via dedicated keys. Better still, the tools in the main toolbar have single-key bindings (e.g., Q for Crop, H for Spot Heal, etc.), so they are easy to remember and use.

Adjustment Layers and Masks

Pixeluvo supports nondestructive editing via so-called adjustment layers (Figure 5). Instead of applying color adjustments directly to the image, you can create a separate layer on top of it and perform edits there. This approach has several obvious advantages. For starters, the original image remains untouched, and you can hide and undo edits by simply disabling or removing the layer. You can also separate different adjustments by creating individual layers. More importantly, if you apply adjustments directly to the image, you can't change them later. Using adjustment layers solves this problem, too.

Figure 5: Pixeluvo supports nondestructive editing via adjustment layers.

Pixeluvo's layer functionality follows the established norms, so if you have ever worked with layers in Gimp (or other image editors), you'll quickly find your way around. And, if you have no previous experience working with layers, Pixeluvo is an ideal platform for mastering this functionality, thanks to the application's focus on simplicity and user-friendliness.

Creating an adjustment layer is a matter of choosing the appropriate entry from the Layer | New Adjustment Layer menu. You can then perform adjustments in a regular manner. Changes you make to a layer apply to all other layers below it. This means that you can control the scope of specific edits by rearranging layers in the current layer stack. The Layers panel in the lower-right corner of the working area can be used to add and manage layers.

The panel contains the current layer stack, and you can rearrange layers by dragging them up and down with the mouse. It's also possible to modify adjustments of a specific layer at any time by double-clicking on the Settings icon next to the desired layer and tweaking the available parameters.

In addition to layers, Pixeluvo supports masks that control which part of the layer should be visible (Figure 6). This functionality can be put to a wide variety of creative uses. For example, if you want to desaturate only a specific area of the image, select the desired area of the image using one of the available selection tools and add a new saturation adjustment layer. Pixeluvo is intelligent enough to automatically convert the selection into the mask in the added adjustment layer, so any adjustments you make will apply only to the selected region.

Figure 6: Pixeluvo makes it easy to work with masks.

You can add a mask to an existing layer, too. Click on the Add Layer Mask icon next to the existing layer, and Pixeluvo turns the current selection into the mask. Mastering layers and masks requires some experimenting, but once you've figured out how to use them, you can achieve rather impressive results.

Pixeluvo and RAW Files

Although Pixeluvo isn't billed as a RAW processor, it's perfectly capable of handling RAW files from most manufacturers (Figure 7). The application gives you full control over exposure, color, and tone curves. You can also adjust brightness and contrast as well as apply the cross-processed filter. Instead of adjusting individual parameters manually, you can let Pixeluvo do the donkey job by pressing the Auto-Exposure button. This usually produces decent results. Pixeluvo places the RAW file in its own layer, and you can use adjustment layers to perform non-destructive editing.

Figure 7: The application can handle RAW files, too.