Unit 4 - Digital Image: beginning with GIMP

Hello again,

We are now learning how to work with Gimp.

Read this text...and then create a new post at your blog. See you on Monday.

source: http://www.gimptalk.com/index.php?/topic/34102-beginning-with-gimp-starting-tutorial-for-new-users/

Beginning with GIMP -- Starting Tutorial for new users

So you have just started with GIMP, and now you are completely lost as to what to do next? There are windows and buttons everywhere and nothing makes sense? If so, this is the tutorial for you. 

The idea is for you to get going with a quick run-through of setting up a vanilla install of GIMP, followed by you doing your first little image in the program.

Installing GIMP

GIMP exists for many different computing platforms, including Linux, Windows and Mac. The current stable versions are 2.6.x and this tutorial will not be fully correct if you are using an older version than 2.6.0. Once GIMP is installed, you can see what version you have in the menu Help->About (to find the menu see below).

• Linux downloads can be found here: http://www.gimp.org/downloads/
• Windows installers here: http://gimp-win.sourceforge.net/
  Photocomix has made a convenient Python-support install package [here], which adds support for the many filters and additions written in Python. Read the install instructions before asking about it. 
• Mac downloads here: http://www.gimp.org/macintosh/

First of all it should be remembered that GIMP's interface is extremely flexible. You can add and remove windows from it as you like.

To the top left you have the Tool box. This contains the most commonly used functions of the program, quite literally the artist's box of utilities. These tools are in fact so often used that almost all of them also have default keyboard shortcuts for even faster access. You are wise to learn most of these by heart if you want to be effective. 

Attached to the bottom of the tool box is the Tool options dock. This shows the settings for each tool and thus changes depending on which tool is currently active. In the image we see the tool options for the paintbrush tool. 

To the far right we have a dock that contains several things in one. What we see at the moment is the empty Layer list window. As we start creating a new image, this list will start to fill with layers.

You also see that there are a bunch of tabs in the upper part of this window, clicking these will bring forth other functionality.

Below the layer list, another dock is attached, containing the list of brushes usable by GIMP. Brushes are, quite like their real-world counterpart, things you use to mark down things on the canvas. They can be used to emulate actual paint brushes, but also be used as "stamps" for creating nice effects, as well as be animated. 

There are two more tabs in this dock, these show lists of patterns and gradients respectively (click them to see). Patterns create seamless mosaics of structure (you could for example use a pattern to paint a checker board). Gradients produce transitions between colours in various ways. All brushes, patterns and gradients can be modified and customized by the user. **this in gray is not so important**

In the center you find the main dock window (Formally this is actually called the Empty Image window). This is the main work area. It starts out small, but it will resize to hold your image when you create or load one. It also is also here you find the menu. To close GIMP you can either close this window or close the tool box (or use the menu File->Quit).

source: http://docs.gimp.org/en/gimp-first-steps.html

This section provides a brief introduction to the basic concepts and terminology used in GIMP. The concepts presented here are explained in much greater depth elsewhere.

Images

Images are the basic entities used by GIMP. Roughly speaking, an “image” corresponds to a single file, such as a TIFF or JPEG file. You can also think of an image as corresponding to a single display window.

A GIMP image may be quite a complicated thing. Instead of thinking of it as a sheet of paper with a picture on it, think of it as more like a stack of sheets, called “layers”. In addition to a stack of layers, a GIMP image may contain a selection mask, a set of channels, and a set of paths.

In GIMP, it is possible to have many images open at the same time.

Layers

If a simple image can be compared to a single sheet of paper, an image with layers is likened to a sheaf of transparent papers stacked one on top of the other. You can draw on each paper, but still see the content of the other sheets through the transparent areas. You can also move one sheet in relation to the others. Sophisticated GIMP users often deal with images containing many layers, even dozens of them. Layers need not be opaque, and they need not cover the entire extent of an image, so when you look at an image's display, you may see more than just the top layer: you may see elements of many layers.

Resolution

Digital images comprise of a grid of square elements of varying colors, called pixels. Each image has a pixel size, such as 900 pixels wide by 600 pixels high. But pixels don't have a set size in physical space. To set up an image for printing, we use a value called resolution, defined as the ratio between an image's size in pixels and its physical size (usually in inches) when it is printed on paper. Most file formats (but not all) can save this value, which is expressed as ppi — pixels per inch. When printing a file, the resolution value determines the size the image will have on paper, and as a result, the physical size of the pixels. The same 900x600 pixel image may be printed as a small 3x2" card with barely noticeable pixels — or as a large poster with large, chunky pixels. Images imported from cameras and mobile devices tend to have a resolution value attached to the file. The value is usually 72 or 96ppi. It is important to realize that this value is arbitrary and was chosen for historic reasons. You can always change the resolution value inside GIMP — this has no effect on the actual image pixels. Furthermore, for uses such as displaying images on line, on mobile devices, television or video games — in short, any use that is not print — the resolution value is meaningless and is ignored, and instead the image is usually displayed so that each image pixel conforms to one screen pixel.

Selections

Often when modify an image, you only want a part of the image to be affected. The “selection” mechanism makes this possible. Each image has its own selection, which you normally see as a moving dashed line separating the selected parts from the unselected parts (the so-called “marching ants” ).

A large component of learning how to use GIMP effectively is acquiring the art of making good selections—selections that contain exactly what you need and nothing more. Because selection-handling is so centrally important, GIMP provides many tools for doing it: an assortment of selection-making tools, a menu of selection operations, and the ability to switch to Quick Mask mode, in which you can treat the selection channel as though it were a color channel, thereby “painting the selection”.

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Now go to your Blog and answer these questions, in a short way:


1-What's Gimp?
2-How can you get Gimp and use it in your computer, at home?
3-Make a list of windows in Gimp.
4-Make a list of words related with digital image.
5-Make a list of words related with using Gimp.
6-Why do we use layers?
7-Is it important to make a selection, when using Gimp?
8-What can you find out in Internet about me? (gimp logo)