Parameters MLx Home | MLx menu | MLx buttons | Widgets | Index | What's New

Use Original 8-bit data

This sets the parameter that controls whether or not to make a copy of the original data that is in turn scaled for display. The default is NO, in which case 8-bit images are treated like other images, in that an 8 bit copy of the image is used for scaling and display. This preserves the original data untouched, and scaling operations can always be 'undone'.

If the parameter is Yes, and if the image loaded is 8 bits (unsigned), then the original image will be modified by scaling operations. But this saves memory for large grayscale images, and makes image display slightly faster, but then you might not be able to recover from scaling operations (without reloading the image).

In programming terms: The image window has an im_array, which is the original data, and an im_scaled_array, which is the copy that has been scaled to 8 bits by one of a number of means. If the original data is already 8-bit, and it is large, then it may be inconvenient to make a duplicate of the original data just for display, as this doubles the memory needed by the image. (Note - displaying the image requires a pixmap, which again is about the same size as the 8 bit array.)


Parameter List

This parameter list controls the behavior of MacLispix. It is automatically saved in the mlx_prefs.lisp file when Mlx quits, and restored when MLx is started.

Other similar parameter lists control the behavior of Widgets and special functions. You will rarely need to access these parameters directly via this list, except perhaps for the crop_bdr parameter.

This dialog gives parameters that can be changed by the user. Double click on one, or select several with the mouse (holding down the command key). Click 'Done' when finished. Here is what the various parameters do:

Preferences File

The mlx_prefs.lisp file a text file that stores the preferences list automatically when MacLispix quits, and reads it when MacLispix starts up. It is in the MLx folder (the same folder as the MacLispix application).