i.Mage Usage

IndexToolsUsageScripting
Concepts
i.Mage has only one "document" open at a time. This document is a linear array of pixels of a given bit depth, either 8 bit indexed colour or 16/24/32 bit true colour. The same document is displayed in both the right and left panes at different zoom levels. The left pane shows the pixels zoomed to a specified level and the right pane shows pixel for pixel.

When you select part of an i.Mage it is copied into whats known as the "brush". The brush is just another bitmap which attaches itself to the mouse cursor as it travels over the document. If you click while holding the brush over the document the brush is combined with the document using the current opererator. The brush is not the windows clipboard. Although it can be easily copyed and pasted to and from the clipboard.

The current operator is the method of combining source colours with the document. The default mode is just to overwrite the document with the source but you can also use binary operators and an alpha operator.

Colour cells and the Palette
Beneath the tools palette is the colour selection and palette. This control allows you to see and edit the current foreground and background colours and the documents palette.

The foreground colour (upper left) and background colour (lower right) can be set by left clicking. A colour selection dialog is opened with various methods of colour selection displayed on different tabs.

You can drag and drop the foreground or background colour to append that colour to the palette by right clicking a dragging to the palette control. Typically this only is useful when editing a true colour document because a paletted document already has a palette.

The palette control shows the current palette. True colour images can have a palette as well, except that it isn't saved with the graphic and doesn't effect the look of the document at all. To edit a colour, double click on it. To select it into the foreground colour, use a single left click. Hold the alt button down to select into the background colour. Right clicking on the palette brings up the palette menu. This allows you to set a range of colours, make gradients, swap ranges, load and save the palette and set the palette to some useful defaults. The copy and paste options don't use the system clipboard but are internal to the palette control itself. You can select a range of entries by clicking and dragging. You can resize the palette using the bottom-right hand corner. The colours reflow to fit the window. This is useful if you want to view the palette in a certain dimension.

If you are editing a paletted document and set the colour to use to a 24 bit colour, i.Mage has to match that to the current document to draw on the image. This may mean that the colour drawn is not exactly the colour selected. Because the colour selected is not available in the current palette. To get an exact colour select from the palette instead of using the RGB sliders.

Views
Zoom (left pane)

The left pane contains the zoomed view of the document. To adjust the zoom level click on the icon. Left click magnifies and right click zooms out. The icon toggles the grid. Right clicking on it brings up the tiling settings. Tiling is drawing a grid line of a different colour every often across the zoomed view. This is useful for drawing icons and other similarly sized objects, like this:

Normal (right pane)

The right pane contains the 1:1 view of the document. Both panes will scroll to keep the portion of the document under the cursor in view. This means when you click and drag outside the visible section of the document the view will scroll in the direction of the mouse.

Undo/Redo
i.Mage has a undo queue that allows you to rollback changes to the document. Remembering this history of information does take memory, the current amount of memory used in the undo queue is shown on the status bar everytime you make a change to the document. When this number becomes too large and you are happy with the current state of the document you can empty the undo queue to reclaim the memory used by using Edit->Discard Undo Queue.

Alternatively you can switch off undo/redo using Edit->Enable Undo to save memory and speed. As some operations require the whole document to be saved to a temporary location in memory so that the changes to the document can be recorded. This takes a small amount of time, right at the start of the draw operation. This can be noticable on large images. Thus there is an option to turn undo off if required. The main offender is the flood fill operation.

© 1999-2006 Matthew Allen