Enblend reference manual
- 1 Enblend
- 2 1. Overview
- 3 2. Invocation
- 4 3. Understanding Masks
- 5 4. Tuning Memory Usage
- 6 5. Helpful Additional Programs
- 7 A. Authors
- 8 B. GNU Free Documentation License
- 9 Program Index
- 10 Option Index
- 11 General Index
- 12 Footnotes
- 13 Table of Contents
- 14 About This Document
This manual is for Enblend (version 3.2-cvs, Thu Sep 25 07:35:10 UTC 2008), a tool for compositing images n such a way that the seam between the images is invisible, or at least very difficult to see.
|Overview of Enblend's features|
|Command line options and arguments|
|How to interpret masks and mask files|
Balancing RAM and swap
|Useful other programs|
|Names of programs referenced|
|Index of all options|
Enblend overlays multiple TIFF images using the Burt-Adelson multiresolution spline algorithm.(1) This technique tries to make the seams between the input images invisible. The basic idea is that image features should be blended across a transition zone proportional in size to the spatial frequency of the features. For example, objects like trees and windowpanes have rapid changes in color. By blending these features in a narrow zone, you will not be able to see the seam because the eye already expects to see color changes at the edge of these features. Clouds and sky are the opposite. These features have to be blended across a wide transition zone because any sudden change in color will be immediately noticeable.
Enblend expects each input file to have an alpha channel. The alpha channel should indicate the region of the file that has valid image data. Enblend compares the alpha regions in the input files to find the areas where images overlap. Alpha channels can be used to indicate to Enblend that certain portions of an input image should not contribute to the final image.
Enblend does not align images. Use a tool as
hugin or PanoTools to do this. The TIFF files produced by these programs are exactly what Enblend is designed to work with. Sometimes these GUIs allow you to select feathering for the edges of your images. This treatment is detrimental to Enblend. Turn off feathering by deselecting it or setting the feather width to zero.
Enblend blends the images in the order they are specified on the command line. You should order your images according to the way that they overlap, for example from left-to-right across the panorama. If you are making a multi-row panorama, we recommend blending each horizontal row individually, and then running Enblend a last time to blend all of the rows together vertically.
Find out more about Enblend on its webpage.
-o OUTPUT-FILE INPUT-FILES....
Assemble the sequence of images INPUT-FILES.... into OUTPUT-FILE.
|Memory and GPU control|
|Mask generation control|
2.1 Common Options
Common options control some overall features of Enblend.
- Pre-assemble non-overlapping images before each blending iteration.
This overrides the default behavior which is to blend the images sequentially in the order given on the command line. Enblend will use fewer blending iterations, but it will do more work in each iteration.
- Write a compressed output file.
Depending on the output file format Enblend accepts different values for COMPRESSION.
- COMPRESSION is a JPEG quality level ranging from 0'100.
- COMPRESSION is one of the keywords:
- Do not compress. This is the default.
- Use the Deflate compression scheme also called ZIP-in-TIFF. Deflate is a lossless data compression algorithm that uses a combination of the LZ77 algorithm and Huffman coding.
- Use Lempel-Ziv-Welch (LZW) adaptive compression scheme. LZW compression is lossless.
- Use PackBits compression scheme. PackBits is particular variant of run-length compression. It is lossless.
- Any other format
- Other formats like the PNG do not accept a COMPRESSION setting.
- Print information on the available options and exit.
- Use exactly this many LEVELS for pyramid blending.
This trades off quality of results for shorter execution time and lower memory usage. The default is to use as many levels as is possible given the size of the overlap regions. Enblend may still use a smaller number of levels if the geometry of the images demands.
- Required option that specifies the name of the OUTPUT-FILE.
- Increase the verbosity of progress reporting. Giving one or more '-v' options will make Enblend more verbose.
- Output information on the Enblend version and some configuration details like extra features that have been compiled in.
- Blend around the ± 180° boundary. Useful for full 360° panoramas. Version 3.2-cvs of Enblend, the one described here, does not blend neither zenith nor or nadir, so you may still see some seams in these areas.
- Checkpoint partial results to the output file after each blending step.
- This option has been deprecated. It is kept for backward compatability with older scripts. Use '--compression=LZW' instead.
2.2 Extended Options
Extended options control the image cache, the color model, and the cropping of the output image.
- Set the BLOCKSIZE in kilobytes (KB) of Enblend's image cache.
This is the amount of data that Enblend will move to and from the disk in one go. The default is 2048KB, which should be ok for most systems.
- Use the CIECAM02 color appearance model for blending colors.
The input files should have embedded ICC profiles if this option is specified. If no ICC profile is present, Enblend will assume that the image uses the sRGB color space. The difference between this option and Enblend's default color blending algorithm is very slight and will be only noticeable when areas of different primary colors are blended together.
- Force the number of bits per channel and the numeric format of the output image.
All DEPTH specifications are valid in lowercase as well as uppercase letters. For integer format use
- Unsigned 8 bit; range: 0..255
- Signed 16 bit; range: -32768..32767
- Unsigned 16 bit; range: 0..65536
- Signed 32 bit; range: -2147483648..2147483647
- Unsigned 32 bit; range: 0..4294967295
For floating-point format use
- IEEE754 single precision floating-point, 32 bits wide, 24 bit significant
- - Minimal normalized value: 1.2 × 10 -38
- - Epsilon: 1.2 × 10 -7
- - Maximal finite value: 3.4 × 10 38
- IEEE754 double precision floating-point, 64 bits wide, 53 bit significant
- - Minimal normalized value: 2.2 × 10 -308
- - Epsilon: 2.2 × 10 -16
- - Maximal finite value: 1.8 × 10 308
If the requested DEPTH is not supported by the output file format, Enblend warns and chooses the DEPTH that matches best.
- Gimp (before version 2.0) and Cinepaint (see section Helpful Additional Programs) exhibit unusual behavior when loading images with unassociated alpha channels. Use option '-g' to work around this problem. With this flag Enblend creates the output image with the associated alpha tag set, even though the image is really unassociated alpha.
- Use the graphics card to accelerate some computations.
This is an experimental feature that may not work on all systems. In this version of Enblend, 3.2-cvs, only mask optimization strategy 1 benefits from this option.
- Set the size of the output image manually to WIDTH× HEIGHT. Optionally specify the X-OFFSET and Y-OFFSET, too.
This option is useful when the input images are cropped TIFF files, such as those produced by
nona. The stitcher
nona is part of Hugin. See section Helpful Additional Programs.
- Set the CACHESIZE in megabytes (MB) of Enblend's image cache.
This is the amount of memory Enblend will use for storing image data before swapping to disk. The default is 1024MB which is good for systems with 3'4gigabytes (GB) of RAM.
- Create an IMAGE-FILE that visualizes the mask optimization process.
This shows Enblend's view of the overlap region and how it decided to route the seam line. If you are experiencing artifacts or unexpected output, it may be useful to include this visualization image in your bug report.
2.3 Mask Generation Options
These options control the generation and the usage of masks.
- Use a scaled-down version of the input images to create the seam line. This is the default.
- Use the full-size images to create the seam line. This can be slow. Use '--fine-mask' if you have very narrow overlap regions.
- Instead of generating a mask, use the one in IMAGE-FILE.
- Turn off seam line optimization. Combined with '--fine-mask' this will produce the same type of mask as Enblend version 2.5.
- Use a two-strategy approach to route the seam line around mismatches in the overlap region. This is the default.
- Save the generated mask to IMAGE-FILE.
Use this option if you wish to edit the location of the seam line by hand. This will give you a template of the right size that you can edit to make your changes. Later, use '--load-mask' to blend the project with your custom seam line.
3. Understanding Masks
A binary mask indicates for every pixel of an image if this pixel must be considered in further processing or ignored. For a weight mask, the value of the mask determines how much the pixel contributes, zero again meaning 'no contribution'.
Masks arise in two places: as part of the input files and as separate files, showing the actual pixel weights prior to image blendung or fusion. We shall explore both occurrences in the next sections.
3.1 Masks in Input Files
Each of the input files for Enfuse and Enblend can contain its own mask. Both applications interpret them as binary masks no matter how many bits per image pixel they contain.
identify or, for TIFF files,
tiffinfo to inquire quickly whether a file contains a mask. Helpful Additional Programs shows where to find these programs on the web.
$ identify -format "%f %m %wx%h %r %q-bit" remapped-0000.tif remapped-0000.tif TIFF 800x533 DirectClassRGBMatte 8-bit ^^^^^ mask
$ tiffinfo remapped-0000.tif TIFF Directory at offset 0x1a398a (1718666) Subfile Type: (0 = 0x0) Image Width: 800 Image Length: 533 Resolution: 150, 150 pixels/inch Position: 0, 0 Bits/Sample: 8 Sample Format: unsigned integer Compression Scheme: PackBits Photometric Interpretation: RGB color Extra Samples: 1<unassoc-alpha> <<<<< mask Orientation: row 0 top, col 0 lhs Samples/Pixel: 4 <<<<< R, G, B, and mask Rows/Strip: 327 Planar Configuration: single image plane
The 'Matte' part of the image class and the 'Extra Samples' line tell us that the file features a mask. Also, many interactive image manipulation programs show the mask as a separate channel, sometimes called 'Alpha'. There, the white (high mask value) parts of the mask enable pixels and black (low mask value) parts suppress them.
The multitude of terms all describing the concept of a mask is confusing.
- A mask defines a selection of pixels. A value of zero represents an unselected pixel. The maximum value ('white') represents a selected pixel and the values between zero and the maximum are partially selected pixels. See Gimp-Savy.
- Alpha Channel
- The alpha channel stores the transpacency value for each pixel, typically in the range from zero to one. A value of zero means the pixel is completely transparent, thus does not contribute to the image. A value of one on the other hand means the pixel is completely opaque.
- The notion 'matte' as used by ImageMagick refers to an inverted alpha channel, more precisely: 1 - alpha. See ImageMagick for further explanations.
Enblend and Enfuse only consider pixels that have an associated mask value different from zero. If an input image does not have an alpha channel, Enblend warns and assumes a mask of all non-zero values, this is, it will use every pixel of the input image for fusion.
nona add a mask to their output images.
Sometimes it is helpful to manually modify a mask before fusion. For example to suppress unwanted objects (insects and cars come into mind) that moved across the scene during the exposures. If the masks of all input images are black at a certain position, the output image will have a hole there.
3.2 Weight Mask Files
4. Tuning Memory Usage
The default configuration of Enfuse assumes a system with 3'4GB of RAM.
If Enfuse has been compiled with the C++-preprocessor symbol
ENBLEND_CACHE_IMAGES it uses its own image cache, whose size is user configurable with the option '-m CACHE-SIZE' (see section Extended Options). Furthermore, option '-b BUFFER-SIZE' (see section Extended Options) allows for fine-tuning the size of a single buffer inside the image cache. Note that CACHE-SIZE is given in megabytes, whereas BUFFER-SIZE is given in kilobytes.
Usually the user lets the operating system take care of the memory management of all processes. However, a user of Enfuse might want to control the balance between the operating systems' Virtual Memory System and Enfuse's image cache for several reasons.
- Paging in or out parts of a process' image runs at kernel level and thus can make user processes appear unresponsive or 'jumpy'. The caching mechanism of Enfuse of course runs as a user process, which is why it has less detrimental effects on the system's overall responsiveness.
- Enfuse's image cache has been optimized for accesses to image data. And all algorithms in Enfuse have been carefully arranged to play nice with the image cache. An operating system's cache has no knowledge of these particular memory access patterns.
- The disk access of the operating system to the swap device has been highly optimized. Enfuse on the other hand uses the standard IO-layer which is a slower interface.
- Limiting the amount of image cache prevents Enfuse from eating up most or all RAM, thereby forcing all user applications into the swap device.
The CACHE-SIZE should be set in a way as to reconcile all of the above aspects even for the biggest data sets (this is many images and large images).
Suggested cache- and buffer-sizes for different amounts of available RAM.
Table 4.1: Suggested cache-size settings
5. Helpful Additional Programs
Several libraries and programs have proven helpful when working with Enfuse and Enblend.
- Raw Image Conversion
- :* DCRaw is a universal raw-converter.
- UFRaw, a raw converter based on DCRaw, adds a GUI (
ufraw), versatile batch processing (
ufraw-batch), and some additional features like, for example, cropping, noise reduction with wavelets, and automatic lens error correction.
- UFRaw, a raw converter based on DCRaw, adds a GUI (
- Image Alignment and Rendering
- :* ALE, David Hilvert's anti-lamenessing engine for the real die-hard command-line users aligns, filters, and renders images.
- Hugin is a GUI that aligns and stitches images.
It comes with several command line tools, like
nona to stitch panorama images,
align_image_stack to align overlapping images for HDR or create focus stacks, and
fulla to correct lens errors.
- Image Manipulation
- :* CinePaint is a branch of an early Gimp forked off at version 1.0.4. It sports much less features than the current Gimp, but offers 8bit, 16bit and 32bit color channels, HDR (for example floating-point TIFF, and OpenEXR), and a tightly integrated color management system.
- High Dynamic Range
- :* OpenEXR offers libraries and some programs to work with the EXR HDR format.
- PFSTools create, modify, and tonemap high-dynamic range images.
- :* LibJPEG is a library for handling the JPEG (JFIF) image format.
tiffinfo command quickly inquires the properties of TIFF files.
- Meta-Data Handling
- :* EXIFTool reads and writes EXIF meta data. In particular it copies meta data from one image to another.
- LittleCMS is the color management library used by Hugin, DCRaw, UFRaw, Enblend, and Enfuse. It supplies some binaries, too.
tifficc, an ICC color profile applier, is of particular interest.
- LittleCMS is the color management library used by Hugin, DCRaw, UFRaw, Enblend, and Enfuse. It supplies some binaries, too.
- Andrew Mihal email@example.com.
B. GNU Free Documentation License
Version 1.2, November 2002
Copyright © 2000, 2001, 2002 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
The purpose of this License is to make a manual, textbook, or other functional and useful document free in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others. This License is a kind of 'copyleft', which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software. We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.
- APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The 'Document', below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as 'you'. You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law. A 'Modified Version' of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language. A 'Secondary Section' is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them. The 'Invariant Sections' are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none. The 'Cover Texts' are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words. A 'Transparent' copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not 'Transparent' is called 'Opaque'. Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only. The 'Title Page' means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, 'Title Page' means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text. A section 'Entitled XYZ' means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as 'Acknowledgements', 'Dedications', 'Endorsements', or 'History'.) To 'Preserve the Title' of such a section when you modify the Document means that it remains a section 'Entitled XYZ' according to this definition. The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.
- VERBATIM COPYING
You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3. You may also lend copies, under the same conditions stated above, and you may publicly display copies.
- COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects. If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages. If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public. It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.
You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:
- Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.
- List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.
- State on the Title page the name of the publisher of the Modified Version, as the publisher.
- Preserve all the copyright notices of the Document.
- Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.
- Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.
- Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.
- Include an unaltered copy of this License.
- Preserve the section Entitled 'History', Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled 'History' in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.
- Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the 'History' section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.
- For any section Entitled 'Acknowledgements' or 'Dedications', Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.
- Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles.
- Delete any section Entitled 'Endorsements'. Such a section may not be included in the Modified Version.
- Do not retitle any existing section to be Entitled 'Endorsements' or to conflict in title with any Invariant Section.
- Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles. You may add a section Entitled 'Endorsements', provided it contains nothing but endorsements of your Modified Version by various parties'for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard. You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one. The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.
- COMBINING DOCUMENTS
You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers. The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work. In the combination, you must combine any sections Entitled 'History' in the various original documents, forming one section Entitled 'History'; likewise combine any sections Entitled 'Acknowledgements', and any sections Entitled 'Dedications'. You must delete all sections Entitled 'Endorsements.'
- COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects. You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.
- AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an 'aggregate' if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document. If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.
Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail. If a section in the Document is Entitled 'Acknowledgements', 'Dedications', or 'History', the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.
You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document 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.
- FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of the GNU Free Documentation 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. See http://www.gnu.org/copyleft/. Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License 'or any later version' applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.
Peter J. Burt and Edward H. Adelson, 'A Multiresolution Spline With Application to Image Mosaics', ACM Transactions on Graphics, Vol. 2, No. 4, October 1983, pages 217'236.
Table of Contents
- 1. Overview
- 2. Invocation
- 3. Understanding Masks
- 4. Tuning Memory Usage
- 5. Helpful Additional Programs
- A. Authors
- B. GNU Free Documentation License
- Program Index
- Option Index
- General Index
About This Document
This document was generated by Christoph Spiel on September, 27 2008 using texi2html 1.78.
where the Example assumes that the current position is at Subsubsection One-Two-Three of a document of the following structure:
- 1. Section One
- 1.1 Subsection One-One
- 1.2 Subsection One-Two
- 1.2.1 Subsubsection One-Two-One
- 1.2.2 Subsubsection One-Two-Two
- 1.2.3 Subsubsection One-Two-Three <== Current Position
- 1.2.4 Subsubsection One-Two-Four
- 1.3 Subsection One-Three
- 1.4 Subsection One-Four
- 1.1 Subsection One-One