Rasterdateien zählen neben Vektordateien zu den gängigsten Dateitypen für digitale Bilder. Einer der wichtigsten Vorteile von Rasterdateien ist, dass sie detailreiche Grafiken und hochwertige Fotos von Digitalkameras darstellen können. Lerne die grundlegenden Funktionen und Verwendungszwecke von Rasterdateien sowie die Unterschiede zwischen Raster- und Vektorbildern kennen.
There are two main types of digital image file — raster and vector. Digital photos and detailed graphics both come in raster form. Popular types of raster files include JPEG, PNG, and GIF images.
However, because their pixel number is fixed, raster images can become distorted or blurry when resized to fill a bigger or smaller space. That’s why vector images are more commonly used for illustrations and logos — vectors are made up of mathematical formulas that can scale up or down infinitely. This means that, compared to pixels, vectors don’t lose their resolution when resized.
Raw photo files, which contain uncompressed image data taken directly from a camera’s sensors, are generally converted to raster files once edited.
Also known as bitmap, raster files work best when you need to store and display high-quality photographs. Most photos come in the raster file format, whether they’re print or digital.
With software like Adobe Photoshop, you can edit individual pixels within a raster file to change the appearance of a photograph. However, each raster image is limited to its individual dimensions and number of pixels, which affects its size and resolution. Increasing the size of an image with too few pixels can cause pixelation, which isn’t usually desirable. That’s why illustrations or logos that need to be used across a variety of sizes often come in vector form.
Advantages and disadvantages of raster files.
If you’re thinking about using a raster file in your next project, make you sure you know the upsides and downsides before you start:
Some of the main advantages include:
Precise editing.
You have the power to individually alter each pixel when editing a raster graphic or photograph. This lets you enhance and tailor the image to your own needs.
The disadvantages of raster files include:
JPEG files compress images and are mainly used for digital photos, while PNG (Portable Network Graphic) files are similar but can also display transparent backgrounds. Animated raster graphics tend to be created as GIF (Graphic Interchange Format) files. Finally, TIFFs (Tagged Image Format File) allow graphic designers to keep editing images without any decrease in quality.
A picture that becomes blurred or distorted when you enlarge the scale to more than 200% is generally a raster image. Only vector files can maintain their exact resolution when you resize them. Raster images will usually have one of the following file extensions:.
.JPEG
.PNG
.GIF
.TIFF
A raster image could work as your logo if it’s only used in one place and the dimensions will always be the same, such as on a business card. If your logo needs to be resized for other uses in print and online — for example, on posters, business cards, or web pages — a vector file would be a better choice because it won’t lose resolution.
If you’re going to be comparing JPEG and PNG files, look at how each format handles image quality and size. By compressing images, JPEG files become smaller and boast faster loading speeds — but this leads to a drop in quality because some data is lost. Comparatively, the compression process used to make PNG images smaller doesn’t affect their quality, but does make their files larger.
Each raster file will contain a different number of pixels, depending on the quality and complexity of the image. Intricate photos taken on high-end digital cameras are likely to have millions of pixels — reflecting the level of detail on display. But always remember — a higher pixel count usually increases the file size.