Image Processing Techniques

OK so I'm back after a few weeks (more like a lot of weeks) of forgetting to publish my blogs (yes I know shame on me but in my defense I was kinda busy and sort of forgot about them) but fear not I'll definitely finish my blogs on lighting and Intro to shaders just not today. So because of last week's (no longer last week's but whatever) nasty snow storm I accidentally left week 4's blog till now (oops I blame people and work for distracting me but whatever). 

So this week's blog is going to focus on Image Processing and before anyone starts being all like 'Oh I know Image Processing cause I know Photoshop, you're wrong (well not wrong per say because I guess you can process images in Photoshop but that's not really what I'm going to talk about).

IMAGE PROCESSING

A Monochrome Image

Now image processing is defined in terms of imaging science as any form of signal processing which inputs an image file and outputs either image or a set of image parameters. Usually when dealing with Image processing most are referring to digital images processing, which focuses on using computer algorithms to manipulate digital images (more can be learned about digital image processing Here), however it can also refer to optical and analog image processing as well (though I won't be focusing on those).

 Now Image Processing focuses on the manipulation and processing of 2D images by a computer, which be anything from simply making an photo change between color and monochrome (meaning that its in black and white) to creating blurs to cause certain aspects of an image to be the focus. Some of the more know and widely used uses of image processing are Image Enhancement (which some people use to make their photos look better than they actually are), Image Restoration (ever have someone restore some of your old pictures? well they used image processing to do that) and Image Compression (ever wonder why some of the videos you download are different sizes for the same video, this is why).

 Examples of Image Processing:

 

 These are just a few changes you can make to an image using Image Processing.

Techniques

Now there are a bunch of different techniques of Image Processing, I will be focusing on the three that my class talked about in our last lecture, which are as followed:

• Blurring
• HDR/Bloom
• Depth of Field

Using these three techniques you can completely change your original image and do some seriously interesting effects, which many people and companies employ when they are creating games, movies and advertisements.

BLURRING

 Now you may be thinking that you know what blurring is, that its when your camera is out of focus or your screen isn't aligned properly (or for those of you who where glasses like me, when you aren't wearing your specs and the world is a giant blog of unfocused stuff) but blurring is a useful tool in image processing.  Well blurring is actually a technique used in a lot of digital art, movies and games in order to achieve certain desired visual effects. One of the most common things blurring is used for is to draw viewer's attentions to certain things in a scene or image.

Example: 

Take this screenshot from Assassin's Creed 3, the game makers used blurring to draw attention to Desmond and the others rather than the background in order to keep gamers focus on the characters. This is an example of the uses and applications of the blurring technique.

Now there are a few different types of Blurring, from box blurring to Motion Blurring, I will be focusing on those in a later blog post in order to go into more detail later.

HDR/BLOOM 

HDR (otherwise known as High-dynamic-range rendering) is a process that uses lighting calculations to render computer graphics scenes. This process creates a more realistic scene because it allows for the presentation of details that can be lost when contrast ratios are limited. You can see the difference HDR makes in the image below, the right side is HDR while the left side is fixed-aperture rendering.

Example:

As you can see the right side displays a much more realistic (and pretty, you can't forget how pretty it is) environment.

Bloom is an effect of computer graphics that reproduces an imaging artifact of real-world cameras, which is used in videos, games and HDR. Bloom produces feather like light which extends from the borders of a bright area in an image.

Examples:

This effect is useful in games that have outside environments or doors/pathways to the outside especially if you are trying create certain effects or wish to draw attention to something other than the background like in the above picture to the left, the bloom in that image helps draw the eye to the character.

 DEPTH OF FIELD

If any of you out there has ever taken photography you either know of or have heard of Depth of Field, for those of you haven't don't worry I'm going to quickly explain what it is (I may or may not go into more detail in another blog, I haven't decided yet). Now Depth of Field is known , in optics (you know film and photography) as the distance between the closest and farthest object in a scene or image. Depth of field is extremely important technique in image processing because using it can change entire look of an image or scene. By changing the Depth of Field you can make an object appear closer than it actually is. For example with image below the flowers seem closer to the edge of the image because the rest of the image isn't in focus.

This is caused by changing the depth of Field, which is an important effect in image processing. An important thing to note about Depth of Field is that it doesn't suddenly change from sharp to unfocused, in a gradual transition since everything in front or behind the focus begins to lose sharpness.

Now for those of you who are interested in the different types of imaging processing techniques I will be posting more blogging about them later. In addition, you can also check out the link below:

•  Various Simple Image Processing Techniques
• Image Processing Techniques

Note: Ok so some of you may be confused with some of the things I have made mention to in this blog like the snow storm (Basically there was this big snow storm that happened in Canada a little while ago and then we had more snow a few weeks later. So just so you are all clear I am talking about the first storm because it took me forever to finish this blog because I was really busy, easily distracted and kinda lazy)