diff options
Diffstat (limited to 'upstream/debian-unstable/man5/pfm.5')
| -rw-r--r-- | upstream/debian-unstable/man5/pfm.5 | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/upstream/debian-unstable/man5/pfm.5 b/upstream/debian-unstable/man5/pfm.5 index c8266a9d..5653a758 100644 --- a/upstream/debian-unstable/man5/pfm.5 +++ b/upstream/debian-unstable/man5/pfm.5 @@ -3,7 +3,7 @@ .\" Do not hand-hack it! If you have bug fixes or improvements, please find .\" the corresponding HTML page on the Netpbm website, generate a patch .\" against that, and send it to the Netpbm maintainer. -.TH "PFM Format Description" 5 "19 April 2012" "netpbm documentation" +.TH "PFM Format Description" 5 "27 February 2024" "netpbm documentation" .SH NAME @@ -19,14 +19,20 @@ the Netpbm converters .BR "\fBpfmtopam\fP" (1)\c \&. .PP -There are multiple similar formats known as PFM in the world, none -of them authoritatively documented. The format described here is one -that Bryan Henderson deduced from a program he found somewhere that -dealt with a "PFM" format. +There are multiple similar formats known as PFM in the world, none of them +authoritatively documented. The format described here is one that Bryan +Henderson deduced from a program he found somewhere that dealt with a "PFM" +format. This format appears to be the one Gimp calls PFM. + +Another important PFM is used by Adobe Photoshop and appears to be identical +to this except that rows are ordered from top to bottom in the Adobe version. +If you interchange images between systems that use these two formats, it will +work except that your image gets flipped upside down. You can compensate for +that with \f(CWpamflip -topbottom\fP. .PP -The PFM format is inspired by the Netpbm formats, and you will see -lots of similarity. It is not, however, an official Netpbm format. -Its goal is not consistent with those of Netpbm formats. +The PFM format is inspired by the Netpbm formats, and you will see lots of +similarity. It is not, however, an official Netpbm format. Its goal is not +consistent with those of Netpbm formats. .SH The format .PP @@ -77,6 +83,11 @@ The raster is a sequence of pixels, packed one after another, with no delimiters of any kind. They are grouped by row, with the pixels in each row ordered left to right and the rows ordered bottom to top. .PP + \fINote:\fP This is the opposite of Netpbm formats, which order rows +top to bottom. It is also the opposite of the format Adobe Photoshop calls +PFM. See the introduction for more information on this disparity. + +.PP Each pixel consists of 1 or 3 samples, packed one after another, with no delimiters of any kind. 1 sample for a grayscale PFM and 3 for a color PFM (see the Identifier Line of the PFM header). |