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Display, 24/8 Bit, and Algorithms Options

The Display Modes Menu

In addition to displaying an image in a window, XV can also display images on the root (background) window of your X display. The Display Modes popup menu lets you select where (and how) XV will display the image. Also, the Display Modes menu lets you specify how colors will be picked to display the image. To view the display modes popup menu, click and hold the Display modes button. The current display mode will be shown with a checkmark next to it. To select a new mode, drag the mouse down to the desired mode, and release the mouse button.

Figure 3 Display, 24/8 Bit, Algorithms

Image Display Modes:

About 8/24 Bit Modes

XV has two primary modes of operation. It can either operate (internally) on 8-bit images with a colormap, or it can operate on 24-bit TrueColor images. In 8-bit mode, any image loaded, be it a 1-bit black-and-white image, or a 24-bit RGB image, will be converted into an 8-bit colormapped image. It will be manipulated as such, and when it is saved, it will be converted back into the appropriate format. Note that when working with 24-bit images, the 24-bit data is thrown away.

In 24-bit mode, the 24-bit data is kept around and manipulated. You can measure pixel values, and if you have a 24-bit display, the image will be shown in 24-bits. If you don't have a 24-bit display, the image will be dithered with a standard set of colors. If you save the image, all 24-bits of the data will be written (assuming the format supports 24-bit images).

The 24/8 Bit Menu

This menu lets you see which mode XV is currently operating in, and lets you change modes. You can also force XV to remain in the current mode and select how the program will convert 24-bit images into 8-bit images.