Newton Developer Technical Information: Newton Programmer's Guide: 2.1 OS Addendum /

Chapter 6 - Drawing and Graphics 2.1 / About Drawing and Graphics in the Newton 2.1 OS

About Gray Pictures

The Newton 2.1 OS can render color PICTs in grayscale. Previous versions could render only black and white PICTs. While the Newton 2.1 OS can process PICTs in up to 32-bit colors, these objects are unnecessarily large. You can save package space by using a graphics program on the desktop machine to convert the PICT to 16 grays using the standard 4-bit palette with.

A PICT specifies its colors as indices to a color table. When NTK or the Newton OS creates a picture, it uses a default a color table. By default the indices are used as the values for the gray tones. The value 0 is white, subsequent values are evenly spaced up to black. Including a color table makes the picture larger, and draw slower.

Note

The RGB values in a color PICT are not modified when rendering it in grays. However, the system only writes and creates PICTs in gray tones. This means that if the user creates a new picture from a color one, the new picture will be defined in gray tones. For example, if a color picture is downloaded from a desktop machine to a Newton device, resized or otherwise edited, and then uploaded to the desktop, it will appear in gray on the desktop machine.