Choosing an incorrect image format for your print can have disastrous consequences with either pixelated graphics in the resulting print or huge file sizes that grind the job to a halt.
In this article you will learn how to avoid this and you will understand the difference between vector and bitmap images and when you should use them.
Vector graphics are created from lines and curves in geometric shapes and are typically used to create logos and illustrations. Vector images are sometimes referred to as line art. Bitmap images or raster images are made up of pixel patterns (tiny dots) to create the image. Bitmap graphics are used to create photographic imagery.
What is a vector?
Vector images tend to be used in logos which are made up of lines and curves. They are resolution-independent, which means they can be scaled using mathematical formulas to maintain the position of the different shapes. Vector images can be scaled to virtually any size without compromising image quality.
Typical vector formats are .ai (Adobe Illustrator file) .eps (Editable PostScript), PDF (Portable Document Format) although these can also contain raster images and .svg (Scalable Vector Graphics) or Scalable Vector Graphics Interchange Format.
When to use a vector graphic?
Vector graphics are used in graphic design because they allow the designer to draw lines and curves to create abstract images widely used in logos and illustrations.
- Using Vector images is advantageous because they can be scaled to any size without compromising the image quality this is great for your printing company
- Vector formats are typically lower in file size than their bitmap counterparts so they take up less space per image
- It’s also easy to edit vector graphics provided you have suitable software such as Adobe Illustrator
What is a bitmap (raster) image?
Raster or Bitmap images are made up of tiny dots called pixels. Different coloured pixels are used to make up images such as photographs. Bitmap images are resolution dependent so will lose picture quality if they are scaled without suitable resolution. On-screen, this resolution is often referred to as PPI (pixels per square inch).
The arrangement of the different coloured pixels in bitmap images is ideal for real-world images such as photographs from digital cameras. Obtaining the appropriate resolution from a bitmap graphic can require a large file size in comparison with vector files.
Editing raster graphics is tricky because it requires the editing of individual pixels using suitable software such as Adobe Photoshop.
Typical bitmap formats are .tiff (Tagged Image File Format) .png (Portable Network Graphics Format) and .jpeg (Joint Photographic Experts Group format).
When to use a bitmap image?
Bitmap or raster images are used in most photographs and images. They are commonly found on websites where the resolution only needs to be as high as the screen it is viewed on (typically 72ppi). Lower resolution is advantageous here as higher quality images at larger sizes can hamper the speed at which a web page loads.
- Bitmaps images are ideal for complex images such as photographs
- Bitmap images are readily available and don’t require expertise to create, as long as the user has access to a digital camera or a scanner
Difference between vector and bitmaps in detail
Vector images are made of geometric shapes, lines and curves which rely on mathematical formulas to maintain their shape. Bitmap images are made up of tiny dots called pixels which are arranged to create the image.
Resizing & resolution
Resizing vector images will not affect the quality because the lines and curves which make up the image are based on mathematical formulas. This makes them ideal for use with large format graphics.
Resizing a bitmap image is possible, but the quality of the bitmap image can be compromised because the individual pixels are fixed in size and position. If a larger image is required the number of individual pixels must be increased.
A Vector image is an efficient way to create illustrations and has a lower file size compared to a bitmap image, especially when a high-quality image is required.
Bitmap image file types jpg, .gif, .png .psd, .tiff
Vector file types .ai, .svg, .ps, .eps, .svf
While both vector and bitmap formats are editable, both require some expertise and software. Vector images are easier to edit in Illustrator due to the nature of the geometrical shapes. Bitmaps require the skill to be edited correctly in software such as Adobe Photoshop. However, simple edits are possible with the software that comes with your digital camera, mobile device or MAC/PC computer.
Professional software such as Adobe Photoshop or Illustrator should be used by a graphics professional although free versions are available.
Vector graphics are ideal for logos and simple illustrations which could be used in various applications. Bitmap graphics are better suited to web applications and conveying complex images such as photographs.
Bitmap vs Vector?
So which of these graphic formats to use? Bitmap graphics vs Vector graphics? Well, that depends on what you are trying to achieve.
As a rule of thumb, if it is to be used again and again in a variety of places and in different sizes, the vector wins out over Bitmap every time.
However, you can’t beat a real-life image to convey a human touch or some personality. As long as you get the correct resolution and file size, then bitmap images also have their place.
If you need advice, get in touch and our experts at Smart Printing Company will be happy to advise you on the best format for your application.