Windows 2000 Graphics API Black Book - Softcover

Chandler, Damon

Softcover

ISBN 10: 1576108767 ISBN 13: 9781576108765

Publisher: Coriolis Group, 2001

Synopsis

Focuses on three vital Windows graphics programming technologies: the Windows Graphics Device Interface (GDI), DirectDraw, and Image Color Management (ICM) 2.0. Contains in-depth coverage of image manipulation, file format management, and ICM technologies. Teaches how to control every aspect of Windows bitmaps, reliably render/capture images to the printer and other devices, and compressing and decompressing images. Demonstrates how to read and write common image file formats, manipulate images in the pixel and frequency domains and cross-dissolve, warp, and morph images.

About this title

About the Author

Michael Fötsch (Graz, Austria) gained his first programming experience when writing text adventures in BASIC at the age of 13. He used to program for VGA and SVGA graphics cards under MS-DOS before he made friends with DirectX and 32-bit Windows. He currently develops graphics and multimedia applications for Windows and DirectX.

Excerpt. © Reprinted by permission. All rights reserved.

[An excerpt from Chapter 16]

Summary of Color Management Systems

There's a lot of information to absorb in this chapter, so before we get our hands dirty with coding, let's recap some of the main concepts from this section. Recall, because different devices have different operating characteristics (e.g., gamut, white point, colorants), a color management system (CMS) is needed to ensure that colors will be displayed accurately regardless of the output device. In Windows, this CMS is called ICM (Image Color Management). The newest version of ICM, version 2, is available only in Windows 98, Windows ME, and Windows 2000.

Device manufacturers convey the particulars of their devices through an ICC device profile, which is often model-specific. Images can also contain a device profile-usually one that's specific to the monitor on which the image was created or to the input device (e.g., a scanner or a digital camera) with which the image was captured. Using information in the image's device profile, the CMS uses a color management module (CMM, or color management method, or color matching method) to convert the image's device-dependent coordinates (color values) to the device-independent coordinates of the profile connection space (PCS). When this image is to be displayed on a monitor, the color management system uses a CMM and the monitor's device profile to convert from PCS device-independent coordinates to the monitor's device-dependent coordinates. Likewise, when the image is to be printed, the color management system uses a CMM and the printer's device profile to convert from PCS device-inde! pendent coordinates to the printer's device-dependent coordinates.

If the destination device doesn't have a corresponding device profile, the CMS assumes that the destination device uses the sRGB color space. If this assumption is incorrect, then the accuracy of the displayed (or printed) image's colors will vary according to how closely the destination device conforms to the sRGB standard. If the source image doesn't have an embedded profile, as is often the case, the CMS assumes that the colors of the image are in sRGB coordinates. If this assumption is incorrect, then the accuracy of the displayed (or printed) image's colors will vary according to how closely the image's colors conform to the sRGB standard.

Keep in mind that ICM doesn't work without the support of applications. Although ICM is the official color management system for Windows, you, as an application developer, must utilize ICM technology to take advantage of the aforementioned benefits. Because very few applications are ICM-aware, Windows has been criticized in many research, academic, and professional communities for its lack of color management support. As we'll discuss next, however, it's not at all difficult to extend your application to be ICM-aware. In fact, now that we've got all of the nitty-gritty, often intimidating, terminology out of the way, the rest is gravy.

Edition details

• Publisher: Coriolis Group
• Publication date: 2001
• Language: English
• ISBN 10: 1576108767
• ISBN 13: 9781576108765
• Binding: Paperback
• Number of pages: 1224