Untitled Document

12/12/2003

Menu bar / Palette / Scale & Colorize w/ table.

This is sort of like arbitrary density slicing. Works on the front image (shift for all images), and uses a text, tab-delimited file for the table. It helps to edit the table in Excel, and export as text, tab delimited.

Output is a byte array, displayed as an image. It is initialized to 0, an arbitrary choice. If 0 is not used in the 'val' collumn, then this value will appear for any pixels with values unspecified in the table.

Table example: see 'scale-palette-table-example.txt'

Format:

1) Comment lines begin with semicolons. Lispix accepts number of comment lines.
2) Collumn titles. Must include these: lo hi val r g b, but the collumns can be in any order, and there can be other collumns.
3) Data. No blank cells.

r, g, and b are the red, green and blue intensities, 0 - 255.

I've found Photoshop handy for choosing the colors. First make a gray level ramp with the required number of gray levels. Export as TIFF, read into Photoshop. Use the color pickers, the paintbucket, and the eye dropper tool to make the color bands you desire. (If you expand the ramp in Photoshop, use nearest neighbor interpolation so that the edges of the bands remain sharp.)

Write as TIF (as an RGB image, NOT an Indexed color image).
Read into Lispix. Use 'Info / pixel info on click' and click the color bands,
one at a time.

Lispix will make a table of the color values, which can then

be cut and pasted into Excel for finishing the table by inputing the color

values.

What the colorizer does: For each value in the input image, Lispix goes down the table seeing if the pixel value is equal to or between the lo and hi limits. If it is, the val for that row is put in the output table, and Lispix goes on to the next pixel. In other words, if the rows overlap a bit (and they probably will at the end points), the first row specifies the color.