06 078972667x CH03 10/23/01 1:57 PM Page 71 3 BITMAP MEMBERS IN THIS CHAPTER Types of Bitmaps 72 Importing Bitmaps 74 Using the Paint Window 76 Bitmap Member Properties 86 Onion Skinning 88 PhotoShop Filters 89 06 078972667x CH03 10/23/01 1:57 PM Page 72 72 Chapter 3: Bitmap Members Images, graphics, illustrations, photographs, and renderings: These are all different names for the same thing as far as Director is concerned. They are all bitmaps: arrangements of colored pixels in computer format. For such content, Director has the bitmap member type. You can create bitmaps in a variety of programs, and then you can bring these images into Director by importing from a variety of standard formats. You can also create and edit bitmaps by using Director’s Paint window. This chapter is dedicated to explaining the bitmap member type and the tasks that Director can do with it. TYPES OF BITMAPS The biggest difference between types of bitmaps is that they can be of different bit depths. There are five different bit depth settings. Bits refer to the amount of information stored for each pixel of a graphic. A 1-bit image has only one piece of information: on or off. An 8-bit image has eight pieces of information, which corresponds to 256 possible combinations. This means that every pixel can have 256 possible colors. Here is a rundown of some of the possi- ble bit depths: • A 1-bit bitmap contains only black-and-white pixels. It’s small, because only “on” or “off” data has to be stored for each pixel, not a color value. 1-bit bitmaps can be useful because you can define the colors of the two types of pixels in them to different colors depending on the sprite. So, a single 1-bit member can be used multiple times to display graphics with different colors. • A 4-bit bitmap contains 16 colors. On the Macintosh, you can customize these 16 colors. In Windows, you can use only one 16-color palette: the Microsoft VGA palette. If you are making your Director movie for a 4-bit machine and intend to distribute it cross-platform, use the Windows VGA palette. • An 8-bit bitmap contains 256 colors. These 256 colors correspond to a color palette. This palette contains black, white, a small range of grays, and a general selection of basic col- ors. You can customize an 8-bit palette both on the Macintosh and in Windows. Director ships with a number of built-in 8-bit palettes. You also can import custom 8-bit palettes into your Director movie either with images that use them, or on their own in the stan- dard palette format (PAL). They are then stored as cast members. • The 16-bit, or thousands of colors, color depth contains 65,536 colors. This color depth was created to closely match the color values of a normal television set. This color depth does not have a palette associated with it. • The 24/32-bit, or millions of colors, color depth contains 16,777,216 colors. This is the max- imum numbers of colors that can be viewed on a computer monitor. This number is actu- ally overkill because a person with normal vision can perceive only about nine million colors. This color depth does not have a palette associated with it. The notation 24/32 might seem a bit odd. The 32 refers to total bits of information: 24 bits for everyday colors and 8 bits that deal with Alpha channel information or other special effects. You can’t, however, work in 24 bits; when 24-bit terminology is used, it actually means a 32-bit resolution. 06 078972667x CH03 10/23/01 1:57 PM Page 73 Types of Bitmaps 73 Using 8-bit images wherever possible is a good idea. An 8-bit image draws faster than a 16- or 32-bit image because the computer can process the smaller 8-bit Two things are conspiring to make image faster than a larger one. However, if your movie 8-bit images obsolete. First, just about every consumer-level com- requires better color, use a higher setting. puter sold in the last three years An 8-bit bitmap can use only 256 colors at one time. is capable of displaying 32-bit However, a technique known as dithering can make the color. Second, Director’s bitmap color range look wider. Dithering is the process of approx- compression and JPEG compres- imating a color by placing pixels of different, but similar, sion for Shockwave movies can colors next to one another. often make 32-bit images almost as small as their 8-bit counter- parts, and these 32-bit images Using Palettes look much better. You can use Director and bitmaps without knowing much at all about palettes, but it helps to understand them. Several palettes are built in to Director. These include the Mac system palette and the Windows system palette. Each acts as a default palette for Director running on the system. Strangely enough, these palettes are not the same. This is where a lot of trouble begins. If you decide to make your movie work with 8-bit graphics, you must choose a palette in the Movie Properties dialog box. But which standard palette do you use? The Mac palette displays fine on Macintosh computers, but not on some Windows machines, and vice versa. In fact, if the user’s monitor is set to use 16- or 32-bit color, the palette issue will never arise. This monitor has enough colors available to display any palette. However, if a computer is set to use an 8-bit monitor setting, it means that it can dis- play only 256 colors at one time. Showing a movie that uses a palette that differs from the If you want to use 8-bit images one the system uses causes the computer to adjust and and you don’t need to stick to a shift to your movie’s palette. This is fine as long as the standard palette, it might be a movie takes over the entire computer screen. However, if good idea to create a new palette a window of another application or the desktop shows that is optimized to display your through, it will display in the wrong colors. collection of graphics as best as possible. This palette can be In addition, showing two 8-bit images that use different imported as a cast member and palettes also causes problems. Two totally different referred to just like the built-in palettes would mean that you are asking the computer to palettes. Programs like display 512 colors at one time. Because it can’t do this, DeBabelizer on the Mac and some of the colors shift. Brenda in Windows can create custom palettes for you. Also, the Using graphics that are 16- or 32-bit also causes problems PhotoCaster Xtra can import a for users with 8-bit displays. The graphics probably use series of PhotoShop images and far more than 256 colors, so Director attempts to compro- create a new palette at the same mise when displaying them. The result might be that time. your graphics do not look very good. 06 078972667x CH03 10/23/01 1:57 PM Page 74 74 Chapter 3: Bitmap Members Choosing the Bit Depth You should think about palettes and bit depth before The Web palette uses only 216 starting your project. What will your users be using? If colors that are shared by both they have 32-bit monitors, you know that you have the palettes. The rest of the colors are option to use 32-bit graphics. If many have only 8-bit not used, but are reserved to capability, 8-bit might be your only option. enable the system to display the desktop and other elements. If your project is focused on deep, complex images, such as photographs, you might want to consider 16- or 32-bit graphics if possible. However, remember that they are two or four times larger than 8-bit bitmaps. Your Director movies will be much larger as a result. However, much of this excess file size disappears when you make Shockwave movies for either the Web or a projector. If you know that most of your users have either Macintosh computers or Windows, the choice of a palette is obvious. Otherwise, consider which one is appropriate for both platforms or per- haps construct a new one. If your movie will end up as a Shockwave movie on a Web site, using Director’s built-in Web palette might be the answer. It displays well on both Mac and Windows. The options can be confusing. If you are just learning Director, stick to using the default palette of your system for now. ➪ For more information on cross-platform development, see “Developing for Both Mac and Windows” p. 700 (Chapter 35, “Cross-Platform Development”) IMPORTING BITMAPS Even though there is only one bitmap member type, a variety of formats can be imported into this bitmap member type. You can import any one of these types of formatted files: • BMP—A common Windows graphic format. • GIF—A format originally used by CompuServe known as the Graphic Interchange Format. It’s now one of the two standard image formats of the Internet. • JPEG—Defined by the Joint Photographic Experts Group as a high-quality compressed image format. It is also a standard image format of the Internet. • LRG—The native format of Macromedia’s xRes image editor.