Gimp Traffic #42 For 14 May 2001

By Cris Flagg

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Table Of Contents

1. Hicolor Pixel Blending

7 May 2001 (2 posts) Archive Link: "hi color pixel blending"

People: Deepak TSven Neumann

Deepak T writes " I am writing a 2D 16 bit color arcade game. I have certain sprites (explosions, glows) which are drawn against a black background, when I draw these against a different background the sprite's edges do not blend with the background and the sprite looks bad, I am not talking about anti-aliasing here, I am talking about reading rgb of source pixel and combining it with rgb of destination pixel to make it look natural (the way it has been drawn against black background). ... But due to lack of vision, all the graphics have been drawn already against black and saved in bitmap format, so I do not have a alpha channel and I have only one layer in the images. Now I cant seem to blend them right with the backgrounds." Sven Neumann suggested using a real alpha channel (using ColorToAlpha would convert the black background to an alpha channel) or color-keying, where the color black stands for "No Color" in the image. Sven also suggests checking out the DirectFB APIs for the Linux frambuffer at (

2. Ermapper / ECW Support

8 May 2001 - 9 May 2001 (4 posts) Archive Link: "Ermapper / ECW Support"

People: Steinar H. GundersonRoel SchroevenGuillermo S. Romero

Tyler Mitchell asked if anyone had added ECW support to the Gimp. The SDK is located at Steinar H. Gunderson wondered how the claim " More people use the ECW technology to compress imagery than any other product" could be correct. Guillermo S. Romero was wary of the patent claims listed on the site. Guillermo thought would be best to avoid more LZW madness and added the company could always supply a plugin themselves. Roel Schroeven agreed that avoiding another LZW fiasco was in everybody's best interest. Roel also pointed out that 'ER Mapper' was aimed at very large bitmaps and orthorectification.

(ed. [Cris Flagg] Patent 6,201,897 for "Transformation and selective inverse transformation of large digital images" ( was issued to Earth Resource Mapping of San Diego, CA on March 13, 2001 )

3. ANNOUNCE: Gimp-Print 4.1.7

8 May 2001 (1 post) Archive Link: "ANNOUNCE: Gimp-Print 4.1.7"

People: Robert L Krawitz

Robert L Krawitz posted the following summary of Gimp-Print 4.1.7

This is gimp-print version 4.1.7, a development release on the 4.1 line.

This software includes the Print plug-in for the Gimp, and GhostScript and CUPS drivers. The support for printers in GhostScript and CUPS is identical to the support for these printers in the Print plugin -- they use the identical code base. Please read src/ghost/README and src/cups/README for more information on this.

The Gimp Print plugin requires the Gimp 1.2.

Gimp-Print 4.1.7 contains the following changes over 4.1.6:

  1. A bug in the internationalization code that prevented compiling on systems not based on GNU libc (for example, Solaris, BSD) is now fixed.
  2. Significant dither improvements, as follows:
    • The Adaptive Random and Random Floyd-Steinberg dither methods have been removed. There is no evidence that they offer any quality enhancement over Adaptive Hybrid and Hybrid Floyd-Steinberg.
    • The Ordered dither method is greatly improved. It now produces correct colors on 6 and 7 color and variable drop size printers. This method is recommended for continuous tone images, as it is faster than Adaptive Hybrid and equal in quality in most cases.
    • The Adaptive Hybrid dither method continues to be recommended for images with a significant component of line art and text, particularly with very fine, sharp detail. It is considerably smoother in transition regions with 6 and 7 color and variable drop size printers, thanks to the improvements in ordered dithering. Tests on an older 6-color printer (Epson Stylus Photo EX) suggest that transitions should be completely invisible to the unaided eye at reasonably high resolutions.
    • Both Ordered and Adaptive Hybrid appear to use less ink (particularly less light ink) on 6 and 7 color printers.
    • Variable drop size Epson printers will exhibit a smoother black transition.
  3. PCL printers will print pages with a lot of vertical white space much more efficiently.
  4. The Epson driver offers more choices of ink types, including 3 and 5 color composite-only inks (black is produced by composition of CMY only; no black ink is used). This may be useful in some cases.
  5. Tentative support for vertical zero margin printing has been added for Epson printers that support it (notably the Stylus Photo 780/790, 890, and 1280/1290 printers). This feature is experimental.
  6. The Gimp plugin name was incorrect in 4.1.6.
  7. The CUPS driver no longer offers the Custom page size as the default; it now offers Letter size as default on most printers.
  8. The CUPS driver no longer allows printing in color to black and white printers (such as laser printers).







Sharon And Joy

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