Technically they functioned a lot like televisions, which scanned beams of electrons from left to right and top to bottom to create moving images. In the mid-1900s the first computer screens were developed. Programs that can help you create raster images include Gimp, Photoshop, and Sketchbook. Some of the most common types of raster image files are gif, jpg, png, psd, and tiff. Nevertheless, freehand drawing with raster graphics has a more natural feel than the vector graphic alternative does, and is more similar to drawing on paper.ĭigital photographs are raster images, as are the images from most freehand drawing programs. On the other hand, very large, high-resolution images can be difficult to work with they can make working in a drawing program with many layers more complicated and slow down your computer. That’s because you’re forcing the same number of pixels with the same amount of information to cover more space. This is what happens when you make existing images bigger and they look “pixelated” or fuzzy. It is impossible to enlarge raster images without losing some information. 600ppi is considered a very high-resolution image.

Typically, online images are 72ppi, whereas print images are about 300ppi. That’s 400 per inch for 160,000 per square inch, times 36 for the entire piece.

For example, a six inch square image with a 400dpi or ppi resolution is expressed through 5,760,000 pixels. Resolution simply refers to the maximum number of pixels per image. Once you zoom back out, the ppi or dpi controls how high resolution the final image is. You can use an image editing program like Photoshop to zoom in and see individual pixels and even edit them. Pixels are individually able to be edited, and they are expressed in either points per inch (ppi) or dots per inch (dpi). Pixels are minuscule colored squares or dots that together make up larger graphics they are the building blocks of images. Raster images, also called raster graphics or bitmap images, are composed of pixels. Here are the basics of raster graphics to get you hooked on the subject. Of course you get a truly in-depth education in raster graphics when you pursue a program in web design, but to pique your interest, we’ve created this brief introduction to raster graphics. If you’re going to work in web design, you need to understand raster graphics.

Example of raster image