(electronic music)
- [Gareth] Hello and welcome to this video tutorial.
Gareth here from TastyTuts.com.
Now, Photoshop is a creative program.
In Photoshop, we copy, paste, duplicate, erase,
color enhance, and transform.
But what exactly are we copying, pasting,
duplicating, erasing, color enhancing, and transforming?
Well, in this tutorial I want to discuss
the basic principals of how images are represented
and exist in Photoshop.
If you're new to Photoshop,
this will give you a good foundation of knowledge.
This will also help you understand various other factors
as we move on in this course.
So to help demonstrate the following principle,
I'm going to use this image here.
If you wish to follow along, you can find this image
in the introduction folder in the project folder.
Now you can download this project folder for free,
the download link is in the description.
So with the project folder open,
click introduction, Raster Image,
and open the raster image document inside,
and you should have something that looks like this.
So every time you open a photo or raw image
in Photoshop, you are essentially working
with a raster image.
Put simply, a raster image
is made with many little square pixels.
Together, these pixels build up a picture
which we see in Photoshop.
Now if I zoom right in on this image here,
we can begin to see some of the square pixels
that are making up this image.
So we can see here that this image is made of many pixels
with many unique colors.
Photoshop manages these pixels and allows us
to modify and arrange them in ways
which allow us to create work of all kinds.
Now, when working with raster images,
there are a few things you need to keep in mind
such as the limitations of working with raster images.
One limitation is scaling.
Now remember, a raster image is made of a particular number
of square pixels.
If we scale an image down like so,
we will retain visual clarity to a certain degree.
By definition, when you scale a raster image down,
you are simply removing pixels to decrease the dimension
of the overall image.
So this image I started with is now smaller
on the canvas area.
It may not contain as many pixels as it did
a second ago, but we can still see clearly
what the image is.
Now, if we scale this back up and above the threshold
of the original size,
Photoshop will create additional pixels
to accommodate for the new size.
The result of this is that the image quality
has been compromised and appears distorted.
We can see here the image is not quite as clear
or legible as the original.
It's looking pretty blurry around the edges here.
A term often used to describe this is pixelated.
As a rule of thumb, you always want to avoid scaling images
up above the original threshold to avoid your image
becoming pixelated and losing quality.
When using images in Photoshop,
we must always seek the highest quality to work with.
This will ensure quality results.
So that's the basic principle of raster images.
As a beginner, understanding the principles
of the raster image is important
as this well help you understand various other factors
that are important and crucial to know in Photoshop.
As we start to work with images in Photoshop,
it is also very important to understand image size,
dimension, and resolution,
what this means and how this works in Photoshop.
In the next video we are going to learn about
image size, dimension, and resolution.
See you in the next video.
(upbeat music)