Hey guys I am Vaibhav and today I am going to discuss about the difference between raster image and vector image. Last time I discussed about Creating a Lens Flare Brush in Photoshop. In this tutorial I am going to discuss the advantages and disadvantages of raster and vector images, when to use raster image and when to use vector image etc.
Have you ever seen this message box while working in Photoshop?
If you are beginner you just click OK without knowing the meaning of it. In fact I also did the same thing for months when I was a beginner without even knowing what is “rasterizing”.
The image you generally works on using Photoshop consists of mainly two categories
What is Raster Image?
The easiest line that can define this is “rater image is made of pixels”.
You might be wondering that if raster image is made of pixels than what is the building block of vector images? I will answer to this question later.
As you can see in the above image, when I zoom in the photo gets distorted and a square shape small blocks starts to appear. These small blocks are called as pixels. You might have heard the term or from somebody else “that picture gets pixelated when I zoom in”. Here pixelated means formation of tiny blocks that starts to appear whenever you zoom in a raster image.
All of us have digital cameras or mobile cameras. When you purchase a digital camera first thing you ask from the shopkeeper is “excuse me sir, this camera is of how many megapixels?”(not generally asked by professional photographers). And then the shopkeeper replies “16 megapixels”. Here 16 MP means the image that you are going to capture with your camera will have 4608 pixels in width and 3456 pixels in height. It should be cleared by now that pixels totally depend on the device that capturing the photo. The size of the pixels depends on the resolution of the photo. More the resolution, more will be the pixels per inch.
This pixels constitutes Raster image.
Extensions that use raster image: Famous extensions that uses raster image is .jpg, .tiff, .gif etc.
What is Vector Image?
Unlike raster image, vector image is made of path. In physics you might have heard the term vectors which means magnitude with direction. Here it also means the same thing, a line with direction. The path is mainly a line which is stroked with color. Paths consists of complex mathematics that tells your monitor and printer how to draw an image. Basically all the animation or graphics that we use in our desktop backgrounds are made of vector images. Best software to create vector image is Adobe Illustrator and CorelDraw.
As these type of images does not contains pixels so no matter how much you zoom in, your image will never be pixelated. I know an idea has already been popped up in your mind. You may just want to google an graphics and download it and then zoom in to check weather it pixelates or not. Well my friends you are trying correct experiment but with wrong apparatus. The image you are downloading from google etc is of JPEG format(99.99% case) which is raster format. As I said in the last line of “raster image” that the extension that uses raster images are jpeg, tiff etc. When you make an graphics and then save it for web in JPEG format in Photoshop than Photoshop automatically converts that vector image to raster image and this process is called rasterizing. Now you might have got the answer of the question that you saw in the massage box in Photoshop many times like I have shown in 1st image in this article.
Note that after rasterizing your layer you will not be able to edit the text, shape etc. You can only apply the graphical transformation.
The above shown picture is the screenshot of the layer panel(years ago it was called as palette) in Photoshop. In the layer panel you can see a rectangular shape icon at the bottom right corner of the layer thumbnail. That symbol shows that layer contains a vector image.
If you want to save your work in vector format without rasterizing it then use the extension .psd(Photoshop Document) .psb or eps. If you used Adobe Illustrator then try to save it to .ai
Want to save File more than 2GB in size?: If you want to save your file that is more than 2GB in size than use .psb format. PSD format is not going to work
And you are done here. Read my next tutorial in which I will be discussing about Creating a New Document in Photoshop. Thank you for reading this article. Hopefully we will meet again in four days.