Difference Between Raster and Vector (With Table)

When an image is resized or zoomed into, at times it turns out to be perfectly clear. However, sometimes the image shows aliasing. This is because of the format of the image, which can either be Raster or Vector. Knowing the difference between the two is pretty important in the field of graphic designing.

Raster vs Vector

The difference between Raster and Vector is that Raster images are made up of coloured pixels that are placed closely together in such a way that they appear to be a picture and not just dots whereas Vector images are made of lines, curves, and fills that are placed at particular coordinates for them to appear as pictures.

Raster images are also commonly known as bitmap images. They are made up of black, white or coloured pixels. Graphic formats including GIF, JPEG, TIFF, XBM, PNG and PCX are used for storing and sharing them. These images are not as scalable as vector images. This is because, on enlargement, the pixel count of the image remains the same, making it look blurry.

Meanwhile, vector images include mathematical expressions which decide the shape, colour and their placement in an image. When an image is resized, the same mathematical formula is applied which results in a larger but clear image. Graphic formats including EPS, WMF, PICT, TrueType and PostScript are used to save and share them.

Comparison Table Between Raster and Vector

Parameters of ComparisonRasterVector
MeaningRaster images are those which are made up of pixels.Vector images are those which are made up of lines, curves, and fills.
Graphic FormatThey use GIF, JPEG, TIFF, XBM, PNG and PCX graphic formats.They use EPS, WMF, PICT, TrueType, and PostScript graphic formats.
ScalabilityThey are not as scalable as the latter.They are easily scalable.
PaintingPainting them is like dipping a brush in paint and using it on a real canvas.On painting, only the outlines of the images get coloured.
UsesThey work best for photo editing.They work best for drawings, illustrations, logos, and other technical imagery.
ProgramsThey can be used in Photoshop, paint shop and GIMP.They can be used in CorelDraw, Illustrator and Inkscape.
ConversionConverting a Raster to a Vector image involves complexity and is time-consuming.Vector images can be converted into Raster images easily.
PrintingIt is difficult to print these images when the spot colours are limited.It is easy to print these images as the number of colours can be changed at the time of printing.
FileA Raster file can be easily converted to other file formats.Vector files cannot be modified or displayed in programs that do not understand the format.
ExtensionsExtensions such as .jpg, .gif, .png, and .tiff are used for these images.Extensions such as .eps, .cdr, .pdf, .ai and .svg are used for these images.

What is Raster?

The term ‘Raster’ is widely used in digital photography and computer graphics. Essentially, it is a mechanism that uses coloured pixels to make up two-dimensional images. These images can be viewed on paper, computer display and other devices. The number of pixels that need to be used for image creation is determined by the height and width of the image.

Raster images are not very scalable. This is because they are only made up of a particular number of pixels. On resizing, the pixels do not increase in count but only become enlarged. Due to this, the resulting image often turns out to be blurry.

Each pixel of a Raster image contains a single numeric value. This value can determine the visible colour and even measurements of the pixel. These pixels are set up in a particular pixel format, which then makes up a Raster grid.

Interestingly, most images that are stored in a computer are of a Raster format. However, most of them are compressed to avoid using large amounts of memory. Regardless, Raster images are widely used in editors such as Paint Shop Pro, Adobe Photoshop, Microsoft Paint and even Coral Painter. These software work on manipulating each individual pixel of the image.

What is Vector?

Like Raster, Vector is a mechanism widely used in computer graphics. It used geometric shapes such as points, curves, lines, squares, and polygons for creating visual images. This mechanism is preferable for fields such as architecture, engineering, typography, surveying, and 3D rendering. However, it cannot be used in digital photography and remote sensing.

Each Vector image consists of a mathematical expression through which the coordinates, colours and measurements of the geometric shapes are designed. When an image is resized, the same mathematical formula is used to change the dimensions. Due to this, the resulting image mostly turns of to be clear. However, there may be aliasing in some images.

These images can be used on software such as Adobe Illustrator, CorelDraw and even Inkscape. For software that does not recognize vector graphics, it is difficult to use these images. However, they can always be converted into raster images with utmost ease.

File formats such as EPS, PDF, CDR, SVG, WMF and AI are most commonly used for such images. Moreover, these images are very ideal for printing images as the numerical values can easily manipulate the colour and dimensions according to the printer requirements. This means that the print will turn out to be clear and crisp even when resized.

Main Differences Between Raster and Vector

  1. Raster images are those which are made up of pixels whereas Vector images are those which are made up of lines, curves, and fills.
  2. Raster uses GIF, JPEG, TIFF, XBM, PNG and PCX graphic formats whereas Vector uses EPS, WMF, PICT, TrueType, and PostScript graphic formats.
  3. Raster images are not scalable whereas Vector images are easily scalable.
  4. Painting Raster is like dipping a brush in paint and using it on a real canvas whereas, on painting vector, only the outlines of the images get coloured.
  5. Raster works best for photo editing whereas Vector works best for drawings, illustrations, logos, and other technical imagery.
  6. Raster can be used in Photoshop, paint shop and GIMP whereas Vector can be used in CorelDraw, Illustrator and Inkscape.
  7. Converting a Raster to a Vector image involves complexity and is time-consuming whereas Vector images can be converted into Raster images easily.
  8. It is difficult to print Raster images when the spot colours are limited whereas It is easy to print Vector images as the number of colours can be changed at the time of printing.

Conclusion

Raster and Vector are two mechanisms that may be difficult to understand for those who do not indulge in computer graphics and digital photography on a regular basis. However, in simple terms, Raster images are made up of pixels whereas Vector images are made up of geometrical shapes such as lines, curves, and polygons.

Moreover, Raster graphics are not scalable because the number and dimensions of the pixel always remain the same whereas Vector graphics are easily scalable because their dimensions change using the common mathematical expression. Each of them has its own benefit when used in different software and for different purposes. 

References

  1. https://ui.adsabs.harvard.edu/abs/1987PgERS..53.1383G/abstract
  2. https://link.springer.com/chapter/10.1007/3-540-45868-9_22
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