Adobe Flash Professional CS5 : Importing Graphics - Understanding Vector and Bitmap Graphics

Introduction

In addition to the vector drawing tools that allow you to create graphics and animation in Flash, you can also import artwork in other formats to use in your Flash movie. Flash has full native support for Adobe Photoshop, Adobe Illustrator, Adobe FXG, BMP, JPEG, GIF, and PNG files, the standard bitmapped graphics. However, you can also import EPS and PDF by using Adobe Illustrator. This allows you to import a variety of different graphic formats into your Flash production process.

Flash drawing tools create and edit vector objects, not pixels, so preparation is necessary for bitmapped graphics in a paint application outside of Flash, such as Adobe Photoshop. Fortunately, Flash allows you to convert a bitmapped graphic into a vector with the Trace Bitmap function. You can also use a bitmap as a fill for vector objects. An important thing to remember is that any bitmap used in your project can add considerable size to your Flash movie. Flash includes several procedures for optimizing these bitmaps on export, through compression settings applied globally, or specifically to each image.

Understanding Vector and Bitmap Graphics

Vector graphics are comprised of anchor points connected to each other by lines and curves, called vectors. These anchor points and vectors describe the contour and surface of the graphic with some included information about color, alpha, and line width. Because they are general descriptions of the coordinates of a shape, they are resolution-independent; that is they can be resized without any loss to the quality of the graphic. Resolution represents the amount of information contained within a linear inch represented by a grid.

Bitmapped graphics are made up of small, colored squares, called pixels that form a grid. Each pixel is given a specific color and a grid of these pixels forms a mosaic, which is your image. Because of this, bitmaps are dependent on resolution (the number of pixels in the grid). Resizing up or down forces pixels to be created or removed to accommodate the new grid size, which can result in a loss of image quality. In Flash, bitmaps look much better on the Stage when severely enlarged or reduced. The smoothing process makes the appearance of these bitmaps in the Flash authoring tool and in Flash Player now consistent.

Both vector and bitmap graphics have their strengths and weaknesses. Vector shapes are simple and graphic in nature. They are a good choice for creating high-contrast, geometric art or art with limited color shifts. If you need to implement artwork with a richer surface texture, color depth, and shading, like those qualities found in a photograph, a bitmap better suits this purpose. The strength of Flash as a content creator is that you can combine the strengths of both vector art and bitmapped art.

Examining Import File Formats

The following image files can be imported into Flash: