diff options
Diffstat (limited to 'pgm.html')
| -rw-r--r-- | pgm.html | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/pgm.html b/pgm.html index 81ecb9fe..fb016389 100644 --- a/pgm.html +++ b/pgm.html @@ -49,8 +49,8 @@ no data, delimiters, or padding before, after, or between images. <OL> -<LI>A "magic number" for identifying the file type. -A pgm image's magic number is the two characters "P5". +<LI>A "magic number" for identifying the file type. +A pgm image's magic number is the two characters "P5". <LI>Whitespace (blanks, TABs, CRs, LFs). @@ -86,7 +86,7 @@ most intense value in the image and any other image to which the image might be compared. <p>Note that a common variation on the PGM format is to have the -gray value be "linear," i.e. as specified above except +gray value be "linear," i.e. as specified above except without the gamma adjustment. <B>pnmgamma</B> takes such a PGM variant as input and produces a true PGM as output. @@ -95,14 +95,14 @@ opaqueness. It is proportional to the fraction of intensity of a pixel that would show in place of an underlying pixel. So what normally means white represents total opaqueness and what normally means black represents total transparency. In between, you would -compute the intensity of a composite pixel of an "under" and -"over" pixel as under * (1-(alpha/alpha_maxval)) + over * +compute the intensity of a composite pixel of an "under" and +"over" pixel as under * (1-(alpha/alpha_maxval)) + over * (alpha/alpha_maxval). Note that there is no gamma transfer function in the transparency mask. </OL> -<p>Strings starting with "#" may be comments, the same as +<p>Strings starting with "#" may be comments, the same as with <a href="pbm.html">PBM</a>. <P>Note that you can use <B>pamdepth</B> to convert between a the @@ -110,16 +110,16 @@ format with 1 byte per gray value and the one with 2 bytes per gray value. <p>All characters referred to herein are encoded in ASCII. -"newline" refers to the character known in ASCII as Line -Feed or LF. A "white space" character is space, CR, LF, +"newline" refers to the character known in ASCII as Line +Feed or LF. A "white space" character is space, CR, LF, TAB, VT, or FF (I.e. what the ANSI standard C isspace() function calls white space). <h3 id="plainpgm">Plain PGM</h3> <P>There is actually another version of the PGM format that is fairly -rare: "plain" PGM format. The format above, which generally -considered the normal one, is known as the "raw" PGM format. +rare: "plain" PGM format. The format above, which generally +considered the normal one, is known as the "raw" PGM format. See <B><A HREF="pbm.html">pbm</A></B> for some commentary on how plain and raw formats relate to one another and how to use them. @@ -176,7 +176,7 @@ also applies. <h2 id="filename">FILE NAME</h2> <p>There are no requirements on the name of a PGM file, but the convention is -to use the suffix ".pgm". "pnm" is also conventional, for +to use the suffix ".pgm". "pnm" is also conventional, for cases where distinguishing between the particular subformats of PNM is not convenient. |