Pnmremap User Manual

From 4ee0e1dcfc013a10729bc0512c0bee14ad480967 Mon Sep 17 00:00:00 2001 From: giraffedata Date: Sun, 26 Apr 2009 20:18:12 +0000 Subject: "miscellaneous update" git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@900 9d0c8265-081b-0410-96cb-a4ca84ce46f8 --- pamaddnoise.html | 5 +++-- pamperspective.html | 2 +- pamsistoaglyph.html | 18 +++++++++++++----- pamstereogram.html | 3 +++ pbmtoepson.html | 6 +++--- pnmremap.html | 32 ++++++++++++++++++++++---------- 6 files changed, 45 insertions(+), 21 deletions(-) diff --git a/pamaddnoise.html b/pamaddnoise.html index 6e9057c5..48a8413a 100644 --- a/pamaddnoise.html +++ b/pamaddnoise.html @@ -38,7 +38,7 @@ pamaddnoise - add noise to a Netpbm image pamaddnoise -type multiplicative_gaussian -[-msigma value] +[-mgsigma value]
@@ -91,6 +91,7 @@ pamaddnoise - add noise to a Netpbm image pamaddnoise treats a PPM image as 3 independent planes, not as a plane of colors in a color space. +

OPTIONS

Used for laplacian noise only. The default value is 10.0. -

-msigma value +

-mgsigma value

Used for mutliplicative gaussian noise only. The default value is 0.5. diff --git a/pamperspective.html b/pamperspective.html index 0573f8eb..618a6c6f 100644 --- a/pamperspective.html +++ b/pamperspective.html @@ -226,7 +226,7 @@ visible part is the smallest possible rectangle that contains the parts specified those three ways.

The visible part must have nonzero size. That means if you specify ---frame-include=no (overriding the default), you'll need to +--frame_include=no (overriding the default), you'll need to specify other frame options in order to have something in the visible part. diff --git a/pamsistoaglyph.html b/pamsistoaglyph.html index 292e394b..657b842b 100644 --- a/pamsistoaglyph.html +++ b/pamsistoaglyph.html @@ -151,6 +151,11 @@ anaglyphs. The algorithm works as follows:

message. +

HISTORY

+ +

Scott Pakin wrote pamsistoaglyph in April 2009. It first appeared +in Netpbm in Release 10.47 (June 2009). +

AUTHOR

@@ -160,10 +165,13 @@ Pakin, scott+pbm@pakin.org.

pam
pamsistoaglyph
ppm3d
Harold W. Thimbleby, Stuart Inglis, and Ian H. Witten. Displaying 3D Images: Algorithms for Single Image Random Dot Stereograms. In IEEE Computer, 27(10):38-48, diff --git a/pbmtoepson.html b/pbmtoepson.html index 7d92d53d..194fc538 100644 --- a/pbmtoepson.html +++ b/pbmtoepson.html @@ -18,7 +18,7 @@ pbmtoepson - convert a PBM image into Epson printer graphics [-dpi=n] [-protocol={escp9|escp}] [-adjacent] -[-noadjacent] +[-nonadjacent] [pbmfile] @@ -75,9 +75,9 @@ print density for you consistent with your other options.
This option was new in Netpbm 10.23 (July 2004).
-adjacent -
-noadjacent +
-nonadjacent -
These options determine whether the output select "adjacent dot +
These options determine whether the output uses "adjacent dot printing" or not, whatever that is.
If you don't specify this, pbmtoepson selects adjacent dot diff --git a/pnmremap.html b/pnmremap.html index 6641929f..d95f9c5c 100644 --- a/pnmremap.html +++ b/pnmremap.html @@ -2,7 +2,7 @@ Pnmremap User Manual
pnmremap
-Updated: 19 February 2009 +Updated: 26 April 2009
Table Of Contents @@ -185,16 +185,22 @@ This names the file that contains the palette image.
-fs
-nofloyd
-nofs +
-These options determine whether Floyd-Steinberg dithering is done. -Without Floyd-Steinberg, the selection of output color of a pixel is based -on the color of only the corresponding input pixel. With Floyd-Steinberg, -multiple input pixels are considered so that the average color of an area -tends to stay more the same than without Floyd-Steinberg. For example, -if you map an image with a black, gray, gray, and white pixel -adjacent, to a palette that contains only black and white, it might -result in an output of black, black, white, white. Pixel-by-pixel -mapping would instead map both the gray pixels to the same color. +These options determine whether pnmremap does Floyd-Steinberg +dithering. Without Floyd-Steinberg, pnmremap selects the output color +of a pixel based on the color of only the corresponding input pixel. With +Floyd-Steinberg, pnmremap considers regions of pixels such that the +average color of a region is the same in the output as in the input. The +dithering effect appears as a dot pattern up close, but from a distance, the +dots blend so that you see more colors than are present in the color map. + +
As an example, if your color map contains only black and white, and +the input image has 4 adjacent pixels of gray, pnmremap with +Floyd-Steinberg would generate output pixels black, white, black, white, +which from a distance looks gray. But without Floyd-Steinberg, +pnmremap would generate 4 white pixels, white being the single-pixel +approximation of gray.
Floyd-Steinberg gives vastly better results on images where unmodified quantization has banding or other artifacts, especially @@ -206,6 +212,12 @@ synonym for -nofloyd.
The default is -nofloyd. +
Before Netpbm 10.46 (March 2009), dithering doesn't work quite as you +expect if the color map has a lower maxval than the input. pnmremap +reduces the color resolution to the color map's maxval before doing any +dithering, so the dithering does not have the effect of making the image, +at a distance, appear to have the original maxval. In current Netpbm, it +does.
-norandom -- cgit 1.4.1

OPTIONS

HISTORY

AUTHOR

SEE ALSO

pnmremap