A tutorial to familiarize with Gimp's interface and begin to know the most important tools for photo editing.
This Gimp's interface tutorial is intended for beginners, although it must be said that if you have never used a photo editing program before it could be considered a little bit too technical; in fact, it has been written for inexperienced users, but assumes a minimum of bases or at least a certain dose of intuition.
Gimp, like all professional softwares, at first glance
can be a little scary. It is full of icons and options that might
alarm those who see it for the first time, but don't worry about it.
One step at a time you will see that in reality it is not at all difficult.
What you see is the default interface, but it if you don't like the appearance, you can completely customize the position and the size of every single window that makes up the Gimp's interface.
The default theme of new versions is dark, and the icons are the new minimalistic "Symbolic icons". The users attached to the previous versions can customize the interface. If you go to Edit - Preferences - Theme you can change the colors of the interface, you can also go to Theme icons to set the traditional icons.
This is the default color scheme.
This is the old color scheme.
On the left there is a window with the icons of all the Gimp's tools, that will be analyzed shortly.
In the center there is s large empty space, in which the photograph will be visible once
opened and on the right there is the part of Gimp's interface dedicated to the layers.
It must be said that some windows are not visible by default, or you would like to hide them; to customize the interface you can access the Windows - Dockable Dialogs menu to make visible everything you need.
Now let's take a closer look at the most important tool's icons of Gimp.
Before starting, however, I would like to say that they not all the tools, will be deepen, but only those that I consider absolutely fundamental in the field of photo editing. Others tools are really interesting powerful, but not for our purposes, so they will not be analyzed. Not all the options will be explained for the same reason.
If you are interested in a complete guide, You can take a look at the official documentation, that will explain everything you need. You can reach it at https://docs.gimp.org/2.10/en/. This tutorial is a summary of the main functions of the interface in the context of photo editing, written for those who do not want to spend a great deal of time reading the official documentation.
I apologize if some parts will not be very clear, but sometimes it's not easy to explain abstract concepts in words, so I always recommend reading the guide with Gimp open, so you can put into practice everything that is described; in this way it will be much easier to understand what I'm trying to explain to you.
Gimp's selections (aka masks):
Rectangle Select Tool: This tool is used for rectangular selections. Pressing CTRL Key the beginning point becomes the center instead, pressing the SHIFT Key you can lock the square aspect ratio. On the Tool Options you can see , if you enable it you can round the corners of the selection.
Ellipse Select Tool: This tool is used for circular or elliptic selections. Pressing CTRL Key the beginning point becomes the center instead, pressing the SHIFT Key you can create perfect circles.
Free Select Tool: This selection has been made for non geometric masks. If you need, as example, to create an exagonal shape, you will have to click six times, one for each vertex of the exagon. Every point you create will be connected to the previous with a straight line. Holding the left mouse button you can draw any shape you want, it could be useful to select, as example, the borders of a mountain. Holding CTRL Key the lines will snap to a 15° degree. To make the selection active, once satisfied of the shape, you have to press the ENTER Key.
Scissors Select Tool: This tool is also called "intelligent scissors", and is really amazing once you master how to use it. I really suggest you to play a little with it to find out how it works. It's really similar to the free select, with one great difference: the selection will try to automatically follow the border of the object you are selecting. Once you have selected all the shape, to activate the selection you have to close it, clicking the beginning point and then click one time with the left mouse button on the inside of the selection boundary.
Fuzzy Select Tool: Fuzzy selection, also called "Magic Wand" allows to select areas with similar colors; For example, in a panorama picture with a blue sky without clouds, if you click any part of the sky it will automatically select the whole sky. Different shades of the same color will be selected, but they have to touch each other. You can change the , to change how much aggressive will be the selection of different shades of the color.
Select by Color Tool: It's extremely similar to the Fuzzy Select Tool with one difference: it considers the similar colors of the whole image, not only the adjacent ones. Also here is possible to change the , to set how much aggressive will be the selection of the different shades of the color.
Every selection has a couple of settings, on the Tool Options, that are the same for every kind of mask. The first common option is the Mode Replace, Add, Subtract and Intersect I think that icons are really clear, anyway let's take as example a pool table: if you need to select all the billiard ball you will have to use Add, if you need to select an apple with a bite, you will use the Elliptic selection and then Subtract to remove the bite. Intersect is easier to understand if you try to make two selection intersecting and see what happens, Replace is the default method, it simply deletes any precedent mask when you make a new one.
Other common settings are that allows to feather (smooth) the borders of the selection, once selected you can change the value of the smooth with the Radius, and finally we can see that improves the quality of the borders of the selction, it's better to leave it always ON.
Other tools on Gimp's interface:
Crop Tool: You can use this tool to crop a photo. You can use rules of thirds as an help for framing, or you can read the specific tutorial for straighten and crop a photo with Gimp, for a deeper explaination of the use of the crop tool.
Color Picker Tool: Clicking any part of the image with this tool will pick the color of the clicked part and selected as Active Foreground Color. The tool considers the selected layer, so if it doesn't work you have another layer selected. If you select and set a radius on the tool will create an average color between the adiacent pixels. Default radius is 2.
Zoom Tool: This tool allows to Zoom In by clicking with left mouse button any part of the image, and Zoom Out by clicking holding the CTRL key pressed. Nevertheless the easistes way to zoom in and out with Gimp is to use the mouse scroll wheel holding the CTRL key pressed. To navigate on a zoomed image you can hold SPACE Bar and move the mouse.
Move Tool: It explains itself, it's used to move the selected level in the work area. It only works if you click on an "occupied" part of the level. I mean that you can't move a layer by clicking on a transparent part on the layer itself.
Rotate Tool: It is used to rotate a selected layer to the right or left. In photo editing is seful to straighten a crooked picture. Rotation can be done by clicking left mouse button and moving cursor, or writing the parameters in the window that appears after clicking. Moving the icon to the center moves the center of rotation. Holding down the SHIFT Key locks the rotation to 15° degrees steps.
Scale tool: It's used to enlarge or shrink the selected layer, Holding CTRL Keyyou can lock the aspect ratio. Scale can be done by clicking left mouse button and moving cursor, or writing the parameters in the window that appears after clicking. It only affects the active layer, if you need to resize a whole picture is better to use Image - Scale Image.
Perspective Tool: This tool is used to correct inclination and perspective of a layer. Once selected you can move as you want the four edges of the layer, to correct perspective distorsions (not lens distorsion). It's mainly used in photo editing, but can be useful.
Flip Tool: Also known as "mirror", is really useful to horizontally or vertically flip a picture. You have to choose Horizontal or Vertical direction in the Tool Options.
Text Tool: This tool is used to add text in Gimp; Important: if you download a font, then you install it Gimp must be closed in order to see the new font, if you forget Gimp opened, you have to close and open it again. If you need to deepen Text Tool, we have a specific tutorial that you can find here.
Bucket Fill Tool:
This tool is created to fill a layer with a color, by clicking left mouse button. If a part of the layer is masked,
it will fill only the selected part.
Holding SHIFT Button the Active Background Color will be used.
In the Tool options you can change the to change the threshold in which different shades of same color are considered similar.
Paintburush Tool: This is the standard draw tool, it has many options for freehand or pen tablet. Clicking the icon down below you can change the brush shape, there are a lot of different options, but the name of the different options will explain itself.
Eraser Tool: This tool is the exact contrary of the Paintbrush Tool: it has the same identical options, but its trait is used to delete instead of paint Clicking the icon down below you can change the eraser shape, there are a lot of different options, but the name of the different options will explain itself.
Clone Tool: This tool is really useful. In the italian website I have a specific tutorial, I'm sorry but for now I have a lot of other more important tutorials to write, but in the near future I will translate also that one.
We hope that the tutorial was useful, now you have to experiment and try, to become perfectly familiar with all the powerful Tools and the Gimp's interface. I recommend you to try all our Gimp guides, and take a look to our photography tutorials who will accompany you in a path of improvement in the use of tools and increasingly advanced devices.