The tools box (or you could say the tools toolbox since this is a floating selection of tools) is the area where you pick the action you want to apply to an image - a selection, text, zoom, color fill, drawing - all are contained within in this box. (Note that to apply an image altering effect to any part of an image, that area must be selected. If in doubt, use Select All from the Select menu.

The buttons on the right of the Tools box, with a small arrow beside them are really groups of buttons with similar functions. For example, you can click on the Rectangular Select button to make it the current tool or you can click on the arrow to reveal further tools. When selected, the current tool appears on top

The two boxes at the bottom of the Tools bar are the Foreground and Background Color boxes. They are interchangeable using the double-arrow button just below. The higher box is always the foreground color and the lower box the background color.

Whenever you use a paintbrush or pencil tool, it is the current foreground color that is applied. Whenever you erase pixels from the background or lowest layer in an image, it is the current background or foreground color, depending on which one you chose in the "New" dialog, that shows through in a printout, in Print Preview or when viewed through a higher transparent layer. You can change the color in either of the boxes by clicking on the box to open up the "Select Color" dialog.

In here you can select a color by using the mouse to drag the crossed lines in the larger box or the single line in the tall thin box. The latter gives you an approximate color range, while the former enables greater fine tuning. Alternatively, you can set a color exactly by entering the right figures for Hue, Saturation, Brightness, Red, Green and Blue in the boxes to the right. You can also use the respective sliders to do this. The result will be displayed immediately in the Preview box. Whichever way you set the color all the relevant indicators will change together to reflect the current color: the color boxes, the Preview box, the sliders, and the measurement boxes. Once you are satisfied, click on OK.

The relevant color box on the Tools bar will be given the new color.

Note that as you change the colors in the Foreground and Background Color boxes, the old ones are stored in the "Recent Colors" dialog. (If this is not visible, select Recent Colors from the View menu.)

Select any of these colors to make it the current Foreground Color. You can use the Color Picker to select a color from an image and make it the Foreground Color.
While we are on the topic of color it is worth mentioning that the Information dialog (select View/Information if this is not visible)

can give you useful data about the color values in an image, amongst other valuable pieces of information (see Information dialog).

The "Information" dialog contains useful information about the color values, selection dimensions and current position of the pointer in an image window. It can be a valuable source of instant information as you work on an image. To open up the dialog, select Information from the View menu.

There are four sections in the dialog:
R G B in the top-left corner gives the respective values (between 0 and 255) for red, green and blue in any color that the pointer is currently passing over.
NOTE - RGB is used for screen and web display
C M Y K in the top-right corner gives the respective percentage values for cyan, magenta, yellow and black in any color the pointer is currently passing over.
NOTE - CMYK is used for projects which you might want to get printed by a printer
X Y in the bottom-left corner gives the coordinates in pixels (horizontal and vertical respectively) of the current pointer position.
W H in the bottom-right corner gives the width and height of a current selection, hence helping you to size selections accurately as you make or edit them.

The Transform options are applicable to both Selections (parts of your image which you can select using various methods) and Images.
They are available either by right clicking over a selection box or by selecting Transform in the Edit menu i.e. after you have selected either the Transform Selection or the Transform Image tool in the Tools box. Note that each of the options transforms either the selection itself or the image within the selection, depending on whether you have chosen Transform Selection or Transform Image respectively.

The options include:

• Scale
  Scale the transformation box either horizontally or vertically by dragging the handles. The selection will be scaled to match the new box dimensions.
• Rotate
  Rotate the transformation box by dragging the double-headed arrow outside the box. The selection will rotate with the box. Note that the star-like symbol acts as the center of rotation and can be repositioned.
• Skew
  Skew the transformation box by dragging a handle in the direction of the line on which it is situated. You can drag the handle in only one direction at a time. The selection will adjust to fit the skewed box. Note that dragging a center-of-line handle moves the whole of the line.
• Distort
  Distort the transformation box by dragging any handle in any direction. The selection will adjust to fit the distorted box. Note that dragging a center-of-line handle moves the whole of the line.
• Perspective
  The dragged handle will move in the direction of the line of the transformation box. If the handle is at a corner, the opposite corner will move the same distance in the opposite direction. Note that dragging a center-of-line handle moves the whole line.
• Numeric
  
  In the "Numeric Transform" dialog set the Position values in the X (horizontal) and Y (vertical) boxes. Leave the Relative box checked if you want the transformation box to move relative to the current position, rather than move to a position starting from the top left-hand corner of the window i.e. X = 0 & Y=0.
  Set the Scale values in the Width and Height boxes. These will scale the width and height of the transformation box. If you want the scaling to be in proportion leave the Constrain Proportions box checked. Whatever you set for the width will also be automatically set for the height, and vice versa. Uncheck the box to set these separately.
  Set the Skew values, in degrees, in the Horizontal and Vertical boxes. You can set the angle of skew anywhere between -60 and 60 degrees.
  Set the Rotate value, in degrees, in the Angle box. The possible values run through -179 (clockwise from the x-axis) to 180 (anti-clockwise from the x-axis) degrees. Note that there is also an Angle Indicator: use your mouse to turn the little circle on the circumference of the big circle to set a new angle. The value in the Angle box will be automatically adjusted.
• Rotate
  Rotate the selection by 180 degrees, 90 degrees clockwise or 90 degrees counter-clockwise.
• Flip
  Flip the selection either horizontally or vertically.

Every time you select a Paint tool a dialog is displayed with an array of brushes. Although the same brushes are common to each of the Paint tools, the dialogs in which the brushes are displayed are slightly different from one another, depending on the particular tool selected.

The brushes vary in size, shape and solidity, and determine how quickly color is applied, toned or erased, and over how large an area. This allows you to work, on the one hand, very quickly with large uniform patches of color, and, on the other hand, to concentrate on the details in a small area of an image. You can switch between brushes with ease.

The two main tools for painting are Pencil and Paintbrush. Whenever you choose a paint tool, you have the option to choose a brush through which the paint tool can be applied. If you do not specifically select a brush, the last brush used by the particular paint tool remains selected. (Pencil produces a "harder" outline than Paintbrush, which employs a technique called "dithering" to soften the edges of a painted shape.)

Whenever you select a brush its name and the number of pixels in the brush shape are displayed above the "Brushes" box. For instance, one of the squares has this attached information: Square <10, 10>. This means that the selected shape is a square that is 10 pixels by 10 pixels. Another option is: Circle, radius = 17 <35, 35>, for a circle with radius 17 pixels, and vertical and horizontal axes through the center of the circle i.e. the diameter, of 35 and 35 pixels respectively.

There are 53 standard brush styles in all. You can create and edit your own brushes by right-clicking in the "Brushes" dialog and selecting an option to open up the "Brush Options" dialog. Alternatively, select the Brush Editor from the Tools menu, where there is a full set of tools for editing and creating brushes.

The effect of applying any Paint tool and therefore the particular brush style used with a tool, is to change the color value of every pixel that comes into contact with the brush. Three concepts relating to the application of Paint tools need to be understood:

• Base color: the pixel color before the brush is applied.
• Blend color: the color you wish to apply.
• Resultant color: the color after the blend color has been combined with the base color using a particular brush style.
These notions are important in understanding the way the various Brush modes work, that is the way the applied color blends with the already existing color. The default value for the blending mode is Normal, as you can see in the Mode box.

Another important concept when selecting a brush style and blend mode is that of opacity, which is set in the Opacity box. If an applied brushstroke has opacity of 100% and the mode is set at Normal, the brushstroke will completely over-paint any color that it comes into contact with. The lower the opacity the more transparent or "see-through" the applied color will be, hence enabling you to see through to the colors beneath. Obviously opacity is a matter of degree and it is certainly worth experimenting with it to understand its full effect.

There is also a comprehensive Brush Editor - where you can design your own brushes.

JPEG Images (*.jpg, *.jpeg) format is ideal for images that are to be used on the web. Since it uses average color values taken from groups of adjacent pixels to compress the image, it is not suitable for high-quality printing. However, on the web the diminution of image quality is more than made up for by the speed of download that compression allows. Typically, a download of several minutes is reduced to just a few seconds.

Note that the format works best with images that have some tonal subtlety, such as photographs of people, rather than ones with large areas of block or flat color (use GIF format instead for these).

Before saving as a JPEG file you can choose some options in this dialog:

• The Quality slider and boxes at the top of the dialog allow you to determine the size and quality of the image. Basically, the smaller the file the lower the quality, the larger the file the higher the quality. The slider and the boxes are automatically adjusted together. Quality runs from 1-100 and can be set in the Quality box. File size can be set anywhere between Small file and Large file using the slider (or use the Size box to select from Low, Medium, High and Maximum). Typically a quality rating of between 40 and 50 will provide a satisfactory file size together with a decent image.
• The Baseline options (in the Format Options section) cause the image to appear one line at a time in your web browser, starting from the top. Optimized slightly reduces the file size when compared to Standard (the default). Note that Baseline JPEGS are becoming rarer, since viewers get impatient with the amount of time it takes to see the whole image.
• The Progressive option causes the image to appear in your web browser in a series of "passes". These allow you to see the image straightaway, albeit in faded form, before the image is fully refreshed. The number of passes is set in the Scan box: the higher the number the quicker the image begins to refresh, although the longer the refreshing takes to complete. Note that at present only a few browsers support Progressive JPEGS, though the situation should improve in the near future.

Below you can see the software in action, this is how easy it is to
change a picture from colour to black and white:

Here is a quick overview of the layers, so you can see how you could change
the background colour of an image: