Online Edition Supported File Formats What Are Bitmap Images? Bitmap images are images that are described by pixels - squares of color arranged in a grid. Bitmap images are also known as raster images. What Are Vector Images? Vector images are images described by shapes such as circles and squares, as opposed to bitmap images which are described by pixels - squares of color arranged in a grid. The shapes are precise mathematical descriptions of the image and can be scaled without becoming blurry or "pixelated" (that blocky look that bitmap/raster images so often get when scaled up). Why Use Vector Images? Vector images are used in most aspects of graphic design and are the preferred format for printing, both on paper and on clothes. The reason for this is that while a bitmap image can look great on the screen, which usually has a resolution of about 72 pixels/dots per inch (DPI), it will normally have to be scaled by a factor of 8 or more when printed since modern printers routinely produce resolutions of 600 pixels/dots per inch. Vector images can handle this type of scaling without any problems while bitmap images struggle with it. Many forms of printing require vector input in order to work - flex printing and embroidery for example. Vector images are also used on the web in for example flash animations. ﷯ JPEG VECTOR Understanding Vector Images Vector images consist of shapes, like circles, rectangles, lines and curves. Each shape is typically made up of a sequence of primitive cursor-based draw operations: move cursor to a point, draw a line to a point, draw a curve with some control points to a point. These shapes are then stroked and / or filled to create the artwork. Stroking means drawing the outline of the shape with some line thickness and some color. The colors used can be either regular solid colors, or various types of gradients. Having the image information in the form of these shapes allows you to scale the image however you like without losing quality, and to do things like have a computer controlled device take a piece of material and then cut it, sew a pattern on it, paint it, etc. This is in contrast to bitmap images where the image information consists of a grid of pixels and the color values at each pixel. These scale poorly, and for applications where you need to e.g. cut, sew, draw, etc, this is insufficient. You can draw the same image in many ways using various shapes and sequences of stroking and filling. Depending on what you're trying to achieve, you may need one arrangement instead of another.
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