Among the many meanings of the word image we mainly will use the one of "an optically formed reproduction of an object, such as formed by a lens or mirror" (Collins).
The term computer graphics encompasses the representation and manipulation of images in digital form. Digital pictures constitute the basis for creating animations.
With computers we can manipulate digital pictures using various technologies.

Digital pictures are coded in form of large arrays of numbers but in order to ensure interoperability, coding standards have to be defined. Animat is able to use all the encoding formats handled by Firefox. Among the various data encoding standards we will throw a closer look to GIF, PNG and APNG.

An animated image is made of a stream of single images together with information on how this images shall be presented on the display. The most important parameter is the time elapsed between the display of consecutive images. The timing will determine whether we will perceive the sequence of presented images as continuous motion. When talking of animated images we usually imply a loop since the sequence is continuously repeated.

An animated image could equally be seen as a short video sequence if played only once, nevertheless this does not provide the full functionality of a video player where you can stop or replay it. Animat stores an animation in a file using the APNG format. This entails that it can be played only on browsers implementing this encoding standard (actually Firefox 3 and Opera 9.5).

A film frame, or simply frame, is one of the many single photographic images in a motion picture. Per analogy this term applies also to a single image part of an animated image sequence.

Traditionally a lightbox is used to examine directly photographic images as slides or as negatives. This term designates in Animat the panel presenting in sequence previews of the images constituting an animation. The sequence can be edited using various commands.

With source image we designate the original image from which a frame is derived in Animat.

An editing session is opened as soon as you start composing an animated image in Animat. The session is persistent, this means you can close the application window at any moment and when you reopen it you will find again its state as you left it.

Note that there can be open only one session per user/computer. The state of an editing session can be saved in a separate file, this way you can resume with it at a later time.

The term transformation used in Animat is related with the same mathematical concept. It describes in term of functions or matrices the whole process of deriving a frame from a source image.

This may encompass something as simple as to cut out a particular area from the source image, or more sophisticated operations like rotate, translate, scale and deform a selected area from the source image and use it to fill the frame.

The application window of animat can be oriented either vertically or horizontally in order to better fit the format of the frames composing the animation.

In either case you will find at the upper edge the menu bar and on the bottom edge the status line whereas the space within the two elements constitutes the work area.

The various panels part of the Animat work area will be described in this chapter as seen in the vertical layout orientation (default), nevertheless the explanations are valid also for the horizontal layout.
The 'switch layout orientation' option in the view menu allows you to change the orientation.

The preferred layout can be selected with the orientation preference.
The position of the edit parameter panel and the lightbox can be changed too via the corresponding preference settings, leading this way to 12 possible work area layouts.

[Fig.53] Mini roses blossom. (Click to see animation)

Strictly speaking this is not an animation but still a valuable and rapid mean to organise a slide show.
Session file: mini-roses.animat

The problem with this kind of animation is that, depending on size and number of the frames, you will get rapidly very big files.

Session file: panorama.animat

When the button with diamond shape is lit the source selection is coupled to the frame selection. At the moment of activation the magnification ratios between frame selection size and source selection size get locked. Any modification of the selection on one side will be applied also to the other side so as to respect the coupling constraints. If you need the offset on the other side to remain fixed you can obtain this with the lock offset action.

Delete the currently selected frame. Note that this does not delete the source image.

This command toggles a frame between enabled and disabled state. When a frame is disabled it will not be included into the generated animated image and its title background turns to gray. This is useful for testing variants. Note that the first frame cannot be disabled, but can be skipped when the animation plays.

Drag and drop images as frames

A bundle of image files from an external directory can be dragged and dropped on any preview frame in the lightbox: a new frame is inserted for every image in the bundle before the pointed preview frame. If the ' Insert sorted' preference is checked they will be inserted in alphabetical order of their names.

Drag and drop a session file

A session file saved with the ' Save the editing session' action can be loaded by dropping it onto the edit parameter panel.

Drag and drop a preview frame

The sequence of animation frames can be reordered by dragging and dropping single preview frames within the lightbox.

Drag and drop a duplicate of a frame

If you keep the control key pressed while dragging a preview frame in the lightbox, the dropped frame will be a duplicate of the original.

Whenever you select a preview frame in the lightbox the parameter settings can be edited in the frame parameter panel.

Extend the selection

Hovering the cursor near the edge inside a selection will mutate it into an extension symbol related to the chosen side. Moving it while keeping the left button pressed allows to change the position of the selection border. The new position is recorded as soon as the button is released.

Extend the selection to the edge

The selection area can be extended to one of the image edges by hovering the cursor near the border to be moved until the cursor mutates into the extension symbol, then while keeping pressed the shift make a click in place.

The manual for Animat can be consulted in a separate browser window. You have further the possibility to report a malfunction or to make a suggestion for an enhancement of Animat.

Insert frames

Insert one or more frames before the currently selected one using the images from the file selection dialog (Inserted in alphabetical order by name if ' Insert sorted' preference is checked).

Insert a local default frame

A click on the Insert default frame in the edit menu will insert a new default frame before the currently selected frame. Local default frames serve as template for default values for the immediately preceding frames.

Load an editing session previously saved with the ' Save the editing session' action. The session file is assumed to have its name terminated by .animat. Note that any current data will be lost unless you saved it before. A session file contains absolute image URLs, therefore you must ensure that this images are still present in the same location otherwise the loading will fail.

Lock the offset

The lock offset button has only an effect when the source selection is coupled with the frame selection. When active the offset will not change when the other selection is modified.

Lock the size ratio

When the lock size ratio is active the ratio between height and with is maintained constant as it was at the moment of activation.

Start a new editing session. Any current data will be cleared. This command helps also to reset Animat to a working state in case a major dysfunction occurred.

The preference menu entry gives you access to the preferences panel. For more details see Preferences.

Close the application.
The name "quit" for the command is somewhat misleading since in Animat the editing session is persistent. When you open the editor you will find it exactly in the state

as you left it the last time with one notable exception however: if any of the source images is removed you will get errors. To restore in such a case the editor state just recover the deleted source images.

Beside reloading the source image (supposed eventually to have changed) this command has the effect to perform a fresh transformation which may also help to clear an error.

When the "reset to default" button attached to a data field (or set of data fields) is lit you can revert the parameter values to defaults. The default value if any is available is made visible through a tooltip. Default values are determined as explained in the ' Parameter area' panel section.

Resize the selection with locked ratio

The selection area can be resized with locked ratio by keeping pressed the control key while extending the selection with the mouse.

Resize the selection centered

The selection area can be resized with its center staying fixed by keeping pressed simultaneously the control key and the shift key while extending the selection with the mouse.

Save the animated image

The animated image is saved into a file with the APNG format.

Save the editing session

All the data data collected in an editing session is comparable to a recipe that describes how the animated image is made. This data can be stored in a file with the 'Save session' action found in file menu.
This file can be loaded again at a later time with the ' Load' action. These action is optional since animat is an application with a persistent state. The filename usually ends with '.animat' .

Select the global defaults panel

At any moment you can switch to the global default frame panel by clicking on the Global tab or by clicking the the Global option in the view menu.

Select the local defaults panel

Provided you have added local default frames, Animat will display the local defaults for a frame if you click on the Local tab or the local option in the view menu. Each frame refers always to the next nearest local default frame when it needs default values. In turn a local default frame refers always to the global default frame permanently positioned at the end of the whole animation sequence.

Select the frame parameter panel

Animat remembers always the last frame you were editing. If the edit frame parameter panel is not visible, a click on the Frame tab will redisplay it with the last edited frame.

Select any frame

Clicking on a preview frame in the lightbox will immediately display the involved source image, transformation parameters and resulting frame in the main work area. You may also step through the sequence of frames in both directions by using the PageUp and PageDown keys.

Select the whole source image

To select the whole source image click in the edit menu Source -> select all. This can also be obtained by Shift + click while pointing with the cursor in the middle of the source image.

Select the whole frame

To select the whole source image click in the edit menu Frame -> select all. This can also be obtained by Shift + click while pointing with the cursor in the middle of the edit frame panel.

Swap with next frame

By clicking in the edit menu 'Swap with next' the currently selected frame is exchanged with the following frame.

Swap with previous frame

By clicking in the edit menu 'Swap with previous' the currently selected frame is exchanged with the preceding frame.

The layout orientation is a setting proper to every session. It can be changed at any time but a user, depending on the animation context, must be prepared in that case to revise some animation parameters. The switching entails the conversion of various parameters which eventually may not to be optimal, therefore it is good practice before switching in the middle of an editing session to save it in a file.

Orientation

This preference determines the layout orientation of the user interface, either 'vertical' or 'horizontal'. If changed this setting will take effect only for new sessions.

State file

The name (without directory path) given to the state file. Leaving the field blank deactivates the permanent state feature.

Parameter panel position

The edit parameter panel can appear at the left, in the middle, or at the right side of the work area for both layout orientations.

Selector parameters

You can chose how the selected area on the source image is put in evidence. Depending on the selected mode additional parameters may be specified like the colour used for the frame, or the fill colour and transparency to be used with dim or highlight modes. Note that the setting will take effect only after selecting a new frame.

Work size

Source images to be used in the animation may vary greatly in size, therefore they will be reduced to the selected source work size in order to keep the use of system resources within reasonable limits.

Load timeout

This setting determines how long Animat will wait for a source image to be loaded before declaring it failed. If many large pictures are loaded at the time you may need to increase this value in order to be able to work without interruptions.

Base path

The string entered here will be used as base path for relative source file names retrieved from a session file. Source file names will be stored in a session file relative to this base path. This can facilitate the transfer of session files between different computer systems.

Selector Parameters

You can chose how the area selected in the target frame is put in evidence. Depending on the selected mode additional parameters may be specified like the colour used for the frame, or the fill colour and transparency to be used with dim or highlight modes. Note that the setting will take effect only after selecting a new frame.

Delay

This is the default delay used when a new session is started.

Dispose

This is the default dispose mode for frames.

Blend

The alpha channel setting determines how the blending will be handled.

Work size

This setting determines the work size of the frame edit canvas. It should also implicitly be considered as the limit size for the animated image.

Size

This is the default size (width and height) given to an animated image.

Image file name

This name (without directory path) will be used to pre-fill the file name field when saving an animated image.

Play count

This is the default number of times an animation is played.

Skip first frame

This sets or resets by default the flag indicating whether the first frame has to be left out when playing the animation.

Autoplay

This flag tells Animat whether to play automatically the animation whenever the context justifies this.

Preview size

Desired with and height for the image presented in the preview frame.

Horizontal lightbox position

When the layout orientation is set to vertical the lightbox extends horizontally. Here you can choose to place it either at the top or the bottom margin of the work area.

Vertical lightbox position

When the layout orientation is set to horizontal the lightbox extends vertically. Here you can choose to place it either at the left edge or at the right edge of the work area. Note that this setting is implicitly influenced by the setting controlling the edit parameter panel.

Insert sorted

If you insert a bundle of images they will be inserted in alphabetically order if the box is checked.

Checker pattern background

You can select here whether the preview image should have a checker pattern as background otherwise the default fill colour for the panel will be used.