This manual describes Irpn Version 0.1.7, which is released under the GNU Public License See License.
Irpn is program for manipulating images. It is designed for technical users such as scientists, who need to manipulate images in a precisely controlled and reproducable way. This sort of thing cannot be accomplished easily with GUI-based tools, and for this reason Irpn is a command-driven program.
The Irpn interface metaphor is a calculator. Indeed, Irpn could be used
solely as an online calculator. Unix users will find it very similar to
the dc ("desk calculator") program. But, in addition to working
with numbers, Irpn lets you work with images as well. As you might add
two numbers in a calculator, you may also add two images in Irpn.
Irpn handles only one image format: the powerful (and free) PNG format.
Irpn may be used in three different ways, with the processing instructions coming from the calling arguments, a file, or by interaction with the user.
Usage is:
irpn [OPTIONS] -- COMMANDSThe items after the
-- are the commands to process. For example,
to copy a file you might do:
irpn -- in.png read copy.png write
NOTE: As is usual for Unix programs, if your COMMANDS contain no
minus signs, the -- is not required. Thus the above could have
been written
irpn in.png read copy.png writebut it's a good idea to include the
-- as a habit, in case the
command contains mathematics with minus signs.
Usage is:
irpn [OPTIONS] filename_with_commands
Here the indicated file contains commands. Corresponding to the previous case, the file might contain
in.ng read copy.png writeor, since formatting doesn't matter, it might contain
in.ng read
copy.png write
etc.
Usage is:
irpn [OPTIONS]In this case, the commands are typed by the user, after a prompt. Depending on the machine on which Irpn was compiled, the
readline
library may be incorporated into Irpn. This enables command history and
command editing using the normal Emacs/Bash/... commands. In
interactive usage, the ? operator is quite handy; use it to see
what's on the stack.
Interactive use gains some new commands, as listed below.
exit
quit
?
#
!...
... (up to the end of the line) to the
operating system as a command. A common command is
!lsto see what files are present.
Below is a sample session:
[kelley@Intrusion irpn]$ ./irpn
> # first, let's see if we have any .png files here.
> !ls
CVS configure irpn-0.1.7.spec irpn_image.o test1.png
Makefile configure.in irpn.cpp operators utilities.h
Makefile.in doc irpn.h rgb.h version
config.cache find_operators.pl irpn.o tags.h
config.log install-sh irpn_image.cpp test
config.status irpn irpn_image.h test1-copy
> # Yup! Let's try copying test1.png into test1-copy.png.
> test1.png read
> ? # make sure it's on the stack
Stack contains 1 item:
image (2 wide, 4 tall)
0/ 0/ 0 0/ 0/ 0
0/ 0/ 0 255/255/255
0/ 0/ 0 255/255/255
255/255/255 255/255/255
> test1-copy.png write # write a copy
> quit # done
Stack contains 1 item:
image (2 wide, 4 tall)
0/ 0/ 0 0/ 0/ 0
0/ 0/ 0 255/255/255
0/ 0/ 0 255/255/255
255/255/255 255/255/255
This chapter is under construction.
To add 100 to the "red" component of each pixel in the image, do the following.
irpn test1.png read 100 0 0 rgb + test1-redder.png write
To extract just the blue channel of an image, do the following.
irpn Kelley_shaved.png read 0 255 - 0 255 - 0 rgb + Kelley_blue_channel.png write
This chapter is under construction.
OPERATOR | STACK-BEFORE |STACK-AFTER | ACTION ----------------------------------------------------------------- [r]ead | Filename | Im | Read image from a file [w]rite | Filename | Im | Write image to a file
filename.png read reads an image and places it on the
stack, in place of the filename that was on the stack before.
filename.png
writes writes it to the named file and then deletes the name from the
stack (leaving the image on the stack).
OPERATOR | STACK-BEFORE |STACK-AFTER | ACTION ---------------------------------------------------------------- + | A B | A+B | Add items - | A B | A+B | Subtract items . | A B | A*B | Multiply items / | A B | A/B | Divide items < | A B | A<B | ***BROKEN*** 1 if A<B; 0 otherwise > | A B | A>B | ***BROKEN*** 1 if A>B; 0 otherwise
number number +
string string +
image number +
image r g b rgb +
number number -
image number -
image r g b rgb -
number number .
image number .
image r g b rgb .
r, g, and b values.
number number /
image number /
image r g b rgb .
r, g, and b values.
OPERATOR | STACK-BEFORE |STACK-AFTER | ACTION ---------------------------------------------------------------- rgb | R G B | rgb_color | create an rgb color
OPERATOR | STACK-BEFORE |STACK-AFTER | ACTION ----------------------------------------------------------------- center | Im F | Im #low #hi| *BROKEN* #low-#high has 100% of graylevel\n\
OPERATOR | STACK-BEFORE | STACK-AFTER | ACTION ---------------------------------------------------------------------------------- boxcar_filt | Im | Im | *BROKEN* Smooth using 3x3 boxcar median_filt | Im | Im | *BROKEN* Smooth using 3x3 median hist_filt | Im | Im | *BROKEN* Flatten histogram subsample | Im ill jll iur jur | Im | *BROKEN* Subsample
OPERATOR | STACK-BEFORE |STACK-AFTER | ACTION ------------------------------------------------------------------------- exch | A B | B A | *BROKEN* Exchange top 2 items on stack pop | ... A B | ... A | *BROKEN* Delete top item on stack duplicate | ... A | ... A A | *BROKEN* Duplicate item on top of stack ? | ... | ... | Show stack contents
*** THESE COMMANDS DO NOT WORK YET ***
OPERATOR | STACK-BEFORE |STACK-AFTER | ACTION ----------------------------------------------------------------------- help | | | Print a help message showhist | Im | Im | *BROKEN* print histogram debug | | | Turn on debugging mode nodebug | | | Turn off debugging mode
This chapter is under construction.
Following a common scheme in Open-Source software, Irpn version names
are made up of three components. These are integers separated by
decimal points, e.g. the current version, 0.1.7.
The leftmost number is the major version number, and it is incremented
for major changes. The rightmost number is a minor version, and it is
incremented for minor changes. The middle number serves two purposes.
First, it is a flag that indicates whether a given version of Irpn is a
so-called "distribution" version (if the number is even) or a so-called
"development" version (if the number is odd). The only changes ever
made to distribution versions are bug fixes. Thus, a version named
1.0.3 will have no new features compared 1.0.2, but it
should correct a bug in the earlier version. On the other hand,
development versions are very changeable, with new features being added
(and possibly deleted) from version to version. Thus, a version
numbered 1.1.23 might add a new feature not found in
1.1.22, but this feature could be removed again in version
1.1.24.
Most users will wish to stick to distribution versions, i.e. versions with even numbers in the middle field.
read.
read for images.
write for images, as well as elementary mathematics on images.
rgb operator See Colors.
hue saturation value HSV operator See Command Reference.
rgb2hsv operator See Command Reference.
hsv2rgb operator See Command Reference.
Adding a new operator requires some knowledge of the C++ programming language, although C programmers should have no problems. It helps if you've used the STL (Standard Template Library) before, but that's not necessary.
The following list outlines the steps in adding a new operator. To be concrete, let's say that we wish to code an operator that examines the stack and prints the type of the item at the top of the stack (if the stack is non-empty), and leaves the stack intact.
$.
$, we'll need to pick something ascii.
We'll call it last_type.
operators directory. This is where code for
operators is contained.
list file, adding a line at the bottom which contains
two items. The first item is the subroutine that will be called to
handle your operator. The second item is the string that represents
your operator. So we add the line
$ last_typeto the end of the
lists file.
template contains a template to help you code your
operator. Copy it to a file named after your operator, i.e.
cp template last_type.cppNote how the filename is constructed by adding
.cpp to the
operator name.
last_type.cpp, and change
NAME_OF_SUBROUTINE to the name of your subroutine, i.e. change
the line
NAME_OF_SUBROUTINE(vector<rpn_item> &s, const char *item)into
myop_sub(vector<rpn_item> &s, const char *item)
The subroutine must return true if the action was successful,
and false if an error occurred. (If an error occurs, you should
print a message before returning.)
The stack is provided in the s variable. It is an STL object
containing items of a type called rpn_item. Consult the file
../irpn.h to see what an rpn_item is, and check the code
for other operators to get ideas. Thus, we might code it up as follows.
#include "../irpn_image.h"
bool
last_item(vector<rpn_item> &s)
{
if (s.size() == 0) {
printf("Stack is of zero length\n");
return true;
}
if (s.back().type == TEXT) {
printf("Top item is textual\n");
return true;
} else if (s.back().type == NUMBER) {
printf("Top item is numerical\n");
return true;
} else if (s.back().type == IMAGE) {
printf("Top item is an image\n");
return true;
} else if (s.back().type == RGB) {
printf("Top item is a RGB triplet\n");
return true;
} else {
printf("Top item is an unknown type.\n");
return false;
}
return true;
}
As the length of the items on the above list demonstrates, by far the
most difficult part is in coding your operator. In many cases, your
code will be much more complicated than the above example. You
should consult the default operators (e.g. add.cpp, for the
addition operator) to learn the tricks of the trade. A C programmer
should be able to get along pretty well, even though the code is in C++.
If you're using images, you'll have to become familiar with the
irpn_image.cpp and irpn_image.h source files, since you
may have to extend them.
It might help to read up on the standard-template library (STL; many sources are available on the web and in textbook), but you probably won't need to, if you mimic the code that comes with Irpn.
If you're doing anything fancy with images, you'll need to read up on the PNG library. The book ("PNG: the definitive guide", by Greg Roelofs, 1999, O'Reilly and Associates Publishing) is better than the online documentation.
Irpn is released under the GNU General Public License, which is given verbatim below.
GNU GENERAL PUBLIC LICENSE
**************************
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
========
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it in
new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get the
source code. And you must show them these terms so they know their
rights.
We protect your rights with two steps: (1) copyright the software,
and (2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software. If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains a
notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program",
below, refers to any such program or work, and a "work based on
the Program" means either the Program or any derivative work under
copyright law: that is to say, a work containing the Program or a
portion of it, either verbatim or with modifications and/or
translated into another language. (Hereinafter, translation is
included without limitation in the term "modification".) Each
licensee is addressed as "you".
Activities other than copying, distribution and modification are
not covered by this License; they are outside its scope. The act
of running the Program is not restricted, and the output from the
Program is covered only if its contents constitute a work based on
the Program (independent of having been made by running the
Program). Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any
warranty; and give any other recipients of the Program a copy of
this License along with the Program.
You may charge a fee for the physical act of transferring a copy,
and you may at your option offer warranty protection in exchange
for a fee.
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a. You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b. You must cause any work that you distribute or publish, that
in whole or in part contains or is derived from the Program
or any part thereof, to be licensed as a whole at no charge
to all third parties under the terms of this License.
c. If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary way, to print or display
an announcement including an appropriate copyright notice and
a notice that there is no warranty (or else, saying that you
provide a warranty) and that users may redistribute the
program under these conditions, and telling the user how to
view a copy of this License. (Exception: if the Program
itself is interactive but does not normally print such an
announcement, your work based on the Program is not required
to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the
Program, and can be reasonably considered independent and separate
works in themselves, then this License, and its terms, do not
apply to those sections when you distribute them as separate
works. But when you distribute the same sections as part of a
whole which is a work based on the Program, the distribution of
the whole must be on the terms of this License, whose permissions
for other licensees extend to the entire whole, and thus to each
and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or
contest your rights to work written entirely by you; rather, the
intent is to exercise the right to control the distribution of
derivative or collective works based on the Program.
In addition, mere aggregation of another work not based on the
Program with the Program (or with a work based on the Program) on
a volume of a storage or distribution medium does not bring the
other work under the scope of this License.
3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms
of Sections 1 and 2 above provided that you also do one of the
following:
a. Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of
Sections 1 and 2 above on a medium customarily used for
software interchange; or,
b. Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a
medium customarily used for software interchange; or,
c. Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with
such an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete
source code means all the source code for all modules it contains,
plus any associated interface definition files, plus the scripts
used to control compilation and installation of the executable.
However, as a special exception, the source code distributed need
not include anything that is normally distributed (in either
source or binary form) with the major components (compiler,
kernel, and so on) of the operating system on which the executable
runs, unless that component itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this
License. However, parties who have received copies, or rights,
from you under this License will not have their licenses
terminated so long as such parties remain in full compliance.
5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify
or distribute the Program or its derivative works. These actions
are prohibited by law if you do not accept this License.
Therefore, by modifying or distributing the Program (or any work
based on the Program), you indicate your acceptance of this
License to do so, and all its terms and conditions for copying,
distributing or modifying the Program or works based on it.
6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program
subject to these terms and conditions. You may not impose any
further restrictions on the recipients' exercise of the rights
granted herein. You are not responsible for enforcing compliance
by third parties to this License.
7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent
issues), conditions are imposed on you (whether by court order,
agreement or otherwise) that contradict the conditions of this
License, they do not excuse you from the conditions of this
License. If you cannot distribute so as to satisfy simultaneously
your obligations under this License and any other pertinent
obligations, then as a consequence you may not distribute the
Program at all. For example, if a patent license would not permit
royalty-free redistribution of the Program by all those who
receive copies directly or indirectly through you, then the only
way you could satisfy both it and this License would be to refrain
entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable
under any particular circumstance, the balance of the section is
intended to apply and the section as a whole is intended to apply
in other circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of
any such claims; this section has the sole purpose of protecting
the integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is
willing to distribute software through any other system and a
licensee cannot impose that choice.
This section is intended to make thoroughly clear what is believed
to be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces,
the original copyright holder who places the Program under this
License may add an explicit geographical distribution limitation
excluding those countries, so that distribution is permitted only
in or among countries not thus excluded. In such case, this
License incorporates the limitation as if written in the body of
this License.
9. The Free Software Foundation may publish revised and/or new
versions of the General Public License from time to time. Such
new versions will be similar in spirit to the present version, but
may differ in detail to address new problems or concerns.
Each version is given a distinguishing version number. If the
Program specifies a version number of this License which applies
to it and "any later version", you have the option of following
the terms and conditions either of that version or of any later
version published by the Free Software Foundation. If the Program
does not specify a version number of this License, you may choose
any version ever published by the Free Software Foundation.
10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the
author to ask for permission. For software which is copyrighted
by the Free Software Foundation, write to the Free Software
Foundation; we sometimes make exceptions for this. Our decision
will be guided by the two goals of preserving the free status of
all derivatives of our free software and of promoting the sharing
and reuse of software generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE
LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT
WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE
QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
SERVICING, REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY
MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU
OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY
OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
=============================================
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these
terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
ONE LINE TO GIVE THE PROGRAM'S NAME AND AN IDEA OF WHAT IT DOES.
Copyright (C) 19YY NAME OF AUTHOR
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
Also add information on how to contact you by electronic and paper
mail.
If the program is interactive, make it output a short notice like
this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19YY NAME OF AUTHOR
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
type `show w'. This is free software, and you are welcome
to redistribute it under certain conditions; type `show c'
for details.
The hypothetical commands `show w' and `show c' should show the
appropriate parts of the General Public License. Of course, the
commands you use may be called something other than `show w' and `show
c'; they could even be mouse-clicks or menu items--whatever suits your
program.
You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the program,
if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright
interest in the program `Gnomovision'
(which makes passes at compilers) written
by James Hacker.
SIGNATURE OF TY COON, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine
library, you may consider it more useful to permit linking proprietary
applications with the library. If this is what you want to do, use the
GNU Library General Public License instead of this License.