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

• The Info->Parameters button in the Miscl collumn of the Image Buttons window displays a list of the parameters and their values. List may be changed and printed.
• Use orig 8-bit Saves memory when reading 8 bit images.

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:

• Auto_show Shows loaded and processed images immediately.
• Crop_bdr Size and position of a rectangle, usually made with the Rect...->Mouse or the Rect...Mouse Adjust button. To clear this parameter, select it and type a space. The bdr (normally a list with four numbers as in the above figure) will be replaced by nil. (The crop&convert widget, for example, will crop images if this rectangle is set, and do no cropping if it is nil (ie. cleared).
  • This parameter is also used by :
    • Averaged profile - in the Stack widget.
    • These Pixels... button functions: Rect->Stats, Chart, Blow Up, Rect Cursor.
    • Crop Image(s) in each Rect... button.
    • The crop image function of the crop&convert widget
  • This parameter is cleared by the clear...graphics button.
• Grid Spacing Controls the spacing in pixels of the grid snap
• Help Browser Sets which HTML browser is used for viewing help files. Netscape is the default, shown as this list. ("Netscape" :MOSS) The second item, :MOSS, is the important one. This is the process ID. To find the process ID for a different HTML browser (or any application for that matter):
  • Load the File Info widget.
  • Select the application with the File Info menu.
  • The Mac file creator will list the desired characters. For Internet Explorer, they are :MSIE. Note that these are CASE SENSITIVE. Make sure when you type them in the dialog that they are preceeded by a colon.
• Mouse Draw Color Color of lines drawn on images using the Draw button, and the Profiles button. Some other graphics may use this color. Set this parameter with the Draw... button.
• Parameter List Length Limit Some parameters may actually be a list of items. This is the maximum number of items that will be displayed for any one parameter in this dialog window.
• Source present Controls the presence or absence of the 'Source' button in the optional help dialogs.
• Use_original_image Default is NO. Set it to yes with the MLx->Image Files->Use Orig 8-bit menu.
• Window_first_click If t, clicking on window selects it AND does the click action, such as moving, or whatever. If nil, then the window needs to be clicked on once to make it the front window, and then subsequent clicks do whatever they are supposed to.
• x_image_dir Not often changed by hand - the directory of the last image loaded.
• Print this list Not really a parameter. Just control for printing the parameter list.
• Save this list Not really a parameter. Just control for saving this list to a text file.

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).