Using The Palace Color Map

What the Heck's a CLUT?





The first thing any Photoshop user (or GC user, or Paintshop Pro user...) should do with Palace is make or get a copy of Palace's custom color map. All Palace pictures are color mapped, like the GIFs we all know and love from our web browsers. All Palace images use the same consistent color palette, so room GIFs and props can be freely intermixed.
Prepackaged CLUT Files for our three hero paint packages are available through the links at the left.
You can make your own palatte file by opening most any Palace room GIF ("pgate.gif" is preferred, since it's guaranteed to have the complete map). They should all have the same map, and your avs should use the same set of colors.
Once you've opened the GIF, select "Color Table..." under the Photoshop "Mode" menu. A dialog will pop up, showing you the color table. Hit the "Save..." button. I saved mine as "Palace.Clut" ("CLUT" = "Color LookUp Table").
For Graphic Converter, use "Save As..." and save as a color table.
For Paint Shop Pro, Use
Colors->Save Palette.
Once the CLUT is saved, you can just hit cancel on any open dialogs and close the GIF file you won't be needing the GIF any more.
The chart below shows the Palace color map, rearranged in seven strips. The top strip shows the map in the order it appears in the GIFs, and thus in Photoshop (The block of blacks at the end of the table is unused). Subsequent strips rearrange the color table, sorting on hue, on saturation, on brightness, on the amount of red, of green, and finally on the amount of blue.
CLUT Strips

Looking at the Color Map The PGate Original Ordering,
and Indexed on Hue, Saturation, Value,
and on Each R G B Component

Clicking on this image will download a copy -- a useful tool for selecting colors (Photoshop can also load the Palace.Clut file directly into the on-screen "Swatches" palette).
Of special interest in the color set should be the block of colors at hues of around 15 degrees or so (easily found in Photoshop by using the color picker -- about one-third of the way across the image in the second row). Sadly, this region is not well-represented, and the colors in it are overly-saturated. Why should we care? Because that part of the color wheel is where all the skintones (worldwide) live. That sometimes makes it very hard to nail a good flat-colored "skin" region on an avatar face especially for flat-colored cartoon characters. Why this color map was made the way it was, I can't answer.

Using the Color Map For any picture you want to use with the Palace, as a room background or a prop, you need to make sure it uses the Palace's color map. Unless the picture started as a Palace image (like the room GIF, or a prop copied from a screen capture), we'll need to convert it to indexed color using the Palace CLUT. There are essentially three kinds of pictures we will convert:

  • RGB (24-bit or 32-bit) full-color images, such as color JPEGs 24-bit is also sometimes known as "16 Million Colors"
  • Grayscale (8-bit, or 256 gray tone) images, such as B&W Photos, JPEG or GIF
  • "Foreign" indexed-color images (such as GIFs you might find on the net) images that use a non-palace color map.
For both grayscale and indexed-color images, you must convert to RGB color first, before converting to indexed color. Photoshop will always assume that grayscale GIFs should be mapped to exactly 256 grayscales; and it has no good way to directly convert from one color table to another. A short time in RGB mode is the neccesary in-between step.
Remember: Save Your RGB Image. You may need it later, for changes or fixes.
To convert an RGB image to the Palace CLUT in Photoshop, you select "Indexed Color..." under
A dialog will pop up. In the "Palette" box, press the "Custom..." button. In the "Dither" box, press whatever you like "None" will generally give you the smallest GIF file size, "Diffusion" shoul give you the smoothest tonal gradations. Palace props aren't stored in GIF or JPEG formats, so dithering makes no difference for their filesize. Now, press "OK."
Another dialog will come up, showing you the color table. If it's still the Palace table (after a while, you'll get to recognize it!), just press "OK." If not, press "Load..." and load our "Palace CLUT" file. Press all the "Okay" buttons. Now, look at your image: it's living in the Palace world.
For GraphicConverter, load the pgate.PAL under the
menu, then
Picture->colors->Change to 256 Colors (8 bit)
For Paintshop Pro, simply select
Colors->Load Palette...
and the conversion will happen in one step, on the spot.

RGB unDith Dith
RGB Original No Dithering Dithered

Not sure about that "Dither" option? Just hit "Undo" and convert it again in several different ways. Or duplicate the image and convert each copy a different way, to compare side-by-side. Above are three samples, superimposed over a bit of Harry's Bar.

Getting the Most
from The Palace Color Map

Think Snappy!

Muddy RGB

The Palace color map is a full color wheel, but it's certainly limited in the choice of colors, compared to "full" 24-bit color images only 236 colors instead of 16 million+. Paint programs can do a super job converting for 24-bit to 8-bit, but you're better-off if you can nudge the process along a bit.
Further, many GIF and other images already have their own color maps what happens to them when we shift to the map used by The Palace?
Let's take a sample pic, with a character from the peerless Giant Robo series (and because no Palace site can have too many good-looking women with big guns...).
Even without masking (which would obliterate even more of the picture) we can see that there aren't a lot of distinct colors in here. Looks like someone was sloppy with the scanner... or maybe the original image was part of some larger picture, with its own contrast range.
Muddy GIF To check how things will all turn out...

  • Duplicate the image in another window
  • Resize to avatar or prop size (I picked 132 pixels)
  • Convert to index-color mode (256 colors), using the Palace Palette
  • Convert to RGB (16 million colors) mode
  • Select "Indexed Color..." again. There in the "Other:" box is the total color count (Or use the "count colors" option in Paintshop Pro). Only 33! And that's including the two or three dithered colors in our unmasked background. Ick!
So what to do?
First, crank up the contrast. I used the Photoshop
dialogue, which gives you a great histogram for feedback. You could get similar (or even identical) results using the "Variations" dialogue or any ther sort of contrast-manipulating tool. I forced the hair values all the way down into the black, and the dress highlight all the way up to white. I also cranked the gamma so that more pixels would end up in the region below the middle gray. The on-screen image in my paint program immediately had loads more "snap."
Sharp GIF Next, I duplicate the image and do a 132-pixel resize, and follow it with a pass of "Unsharp Mask." Now, converting to Palace palette, we get more than twice as many colors: our convert/convert-back check shows 73 colors present in this version, a great improvement.
In this X's experience, beating on the original image's contrast and gamma ranges are the number one line of defense against muddy and incoherent palace prop images. The more colors you can get into the final prop, the clearer it will be.
Shifting from one color map to another can present its own suite of problems. Fortunately, many indexed-color images found on the web already use the Netscape palette, which is very similar to the palette used by The Palace. When in doubt: call up the original image, duplicate it, convert to RGB, then convert to the Palace CLUT, and view them all together.
The most common problem in index-to-RGB-to-index conversions is dither noise (sometimes a problem with low-quality JPEGs, too). Functions like "despeckle" and "blur" can do a lot to solve it convert to RGB, run the filter, then convert to the Palace palette. In this illustration, note especially the tones between the nose and nearer cheek.

wrong map direct despeckled
An "alien" color-mapped image with 64 colors Direct conversion to the Palace color palette ...Using Photoshop's RGB "Despeckle" filter

Revised 30 Dec 1998
The undithering problem is really just a subtle variant of the halftone moiré problem so common in scanning from books and magazines. Despeckling and blurring will smooth-out the colors of the original image, creating new intermediate colors that can subsequently be more effectively re-dithered into the palace palette. You may also find that the problem is more-pronounced in one RGB color channel (say, green) than the others... so sometimes a careful bit of smudging by hand in just that one channel can be in order.