Digital colour fundamentals everyone should know

Before using the Histogram or other tools will make sense, we need to cover how electronic devices reproduce full-colour images using only red, green and blue light.

The histogram is probably the most important tool in your toolset to instantly see why an image doesn't look good and how to improve it. A histogram is a pixel sorter that shows you exactly how many pixels your photo has of each of the 3 base colours (red, green and blue), from dark(black) to bright. The number of totally black pixels is shown on the left and the number of white pixels is shown on the right. All the shades from dark(black) to bright are shown in between. This lecture will explain this in more detail and how to use the histogram to create perfectly lit images.

This short lecture was added later after I started experimenting with a hobby laser engraver to engrave images onto various types of wood. It seems like a trivial task if you have an image, wood and a laser engraver, but it's not.

In this lecture we discuss a very practical use of the histogram to ensure the best possible results when engraving images on various materials.

useful test pattern is also provided which can be used to test the laser on a new material before committing a whole image.

Colour Levels is the next toolset you need to give you even more control over an image. Where brightness, contrast and the histogram input and output affect the image as a whole, the colour levels tools give you control over each colour band individually. In this lecture, you will see how this course's thumbnail image (underwater image) was corrected from a dull and overall greenish photo on the left to the corrected one on the right.

Here I show you where and how to download a safe and free copy of GIMP, a powerful product for any image manipulation and creation, which you will use in this course.

Don't use the normal "File > Open" route to open photos in GIMP. There are much quicker and easier ways to do which will be shown here.

In this wiondow I will quickly show you how to setup GIMP  in single window mode and what that means

Highly Recommended: One setting that will save you hours of frustration is to link the scroll of your mouse wheel to the zoom function in your GIMP view window. Here I show the the few steps to get that done.

In this lecture you will learn how to use a few other tools of GIMP to create special grey scale (aka black and white) image where a selected area or object remain in colour - a similar effect as what you would get by colouring in a black and white photograph by hand with colour.