1enblend(1) enblend(1)
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6 enblend - combine images using a multiresolution spline
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9 enblend [OPTIONS] -o output-file input-files...
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12 Enblend overlays multiple TIFF images using the Burt & Adelson mul‐
13 tiresolution spline. This technique tries to make the seams between
14 the input images invisible. The basic idea is that image features
15 should be blended across a transition zone proportional in size to the
16 spatial frequency of the features. For example, objects like trees and
17 windowpanes have rapid changes in color. By blending these features in
18 a narrow zone, you will not be able to see the seam because the eye
19 already expects to see color changes at the edge of these features.
20 Clouds and sky are the opposite. These features have to be blended
21 across a wide transition zone because any sudden change in color will
22 be immediately noticeable.
23 Enblend expects each input TIFF to have an alpha channel. The alpha
25 channel should indicate the region of the file that has valid image
26 data. Enblend compares the alpha regions in the input files to find the
27 areas where images overlap. Alpha channels can be used to indicate to
28 Enblend that certain portions of an input image should not contribute
29 to the final image.
30 Enblend does not align images for you. Use a tool like Hugin or Pan‐
32 oTools to do this. The TIFFs produced by these programs are exactly
33 what enblend is designed to work with. Sometimes these GUIs allow you
34 to select feathering for the edges of your images. This treatment is
35 detrimental to Enblend. Turn off feathering by deselecting it or set‐
36 ting the feather width to zero.
37 Enblend blends the images in the order you specify on the command line.
39 You should order your images according to the way that they overlap,
40 for example from left-to-right across the panorama. If you are making
41 a multi-row panorama, I recommend blending each horizontal row individ‐
42 ually, and then running Enblend a final time to blend all of the rows
43 together vertically.
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47 -a Pre-assemble non-overlapping images before each blending itera‐
48 tion. This overrides the default behavior which is to blend the
49 images sequentially in the order given on the command line.
50 Enblend will do fewer blending iterations, but it will do more
51 work in each iteration.
52 -h Print information on the available options.
54 -l num Use exactly this many levels for pyramid blending. This trades
56 off quality of results for faster execution time and lower mem‐
57 ory usage. The default is to use as many levels as possible
58 given the size of the overlap region. Enblend may still use a
59 smaller number of levels if the geometry of the images demands
60 it.
61 -o output-file
63 Required. Specify the name of the output file.
64 -v Verbose output.
66 -w Blend around the -180/+180 boundary. Useful for full-360 panora‐
68 mas. Enblend currently does not blend the zenith or the nadir,
69 so you may still see some seams in these areas.
70 -z Use LZW compression for the output images.
72 -x Checkpoint partial results to the output file after each blend‐
74 ing step.
75 input-files
77 Two or more TIFF files.
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81 -b kilobytes
82 Set the block size for Enblend's image cache. This is the amount
83 of data that Enblend will move to and from the disk in one go.
84 The default is 2 MiB which should be good for most systems.
85 -c Use the CIECAM02 color appearance model for blending colors.
87 Your input TIFF files should have embedded ICC profiles. If no
88 ICC profile is present, Enblend will assume that image uses the
89 sRGB color space. The difference between using this option and
90 Enblend's default color blending algorithm is very slight, and
91 will be most noticeable when you need to blend areas of differ‐
92 ent primary colors together.
93 -g Gimp (ver. < 2) and Cinepaint exhibit unusual behaviors when
95 loading images with unassociated alpha channels. Use the -g flag
96 to work around this. With this flag Enblend will create the out‐
97 put image with the associated alpha tag set, even though the
98 image is really unassociated alpha.
99 --gpu Use the graphics card to accelerate some computations. This is
101 an experimental feature and it may not work on all systems.
102 Currently, only mask optimization strategy 1 benefits from this
103 option.
104 -f WIDTHxHEIGHT
106 Set the size of the output image manually. This is useful when
107 the input images are cropped TIFF files, such as those produced
108 by Nona.
109 -m megabytes
111 Set the size of Enblend's image cache. This is the amount of
112 memory Enblend will use for storing image data before swapping
113 to disk. The default is 1 GiB.
114 --visualize=FILE
116 Create an output image that visualizes the mask optimization
117 process. This shows Enblend's view of the overlap region and
118 how it decided to route the seam line. If you are experiencing
119 artifacts or unexpected output, it may be useful to include this
120 visualization image in your bug report.
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124 --coarse-mask
125 Use a scaled-down version of the input images to create the seam
126 line. This is the default.
127 --fine-mask
129 Use the full-size images to create the seam line. This can be
130 slow. Use this option if you have very narrow overlap regions.
131 --optimize
133 Use a two-strategy approach to route the seam line around mis‐
134 matches in the overlap region. This is the default.
135 --no-optimize
137 Turn off seam line optimization. Combined with --fine-mask, this
138 will produce the same type of mask as Enblend 2.5.
139 --save-mask=FILE
141 Save the generated mask to an image file. Use this option if
142 you wish to edit the location of the seam line by hand. This
143 will give you a template of the right size that you can edit to
144 make your changes. Then, use the --load-mask option to blend
145 the project with your custom seam line.
146 --load-mask=FILE
148 Instead of generating a mask, use the one in the given file.
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152 Please see the Enblend web page at:
153 http://enblend.sourceforge.net/
155
158 Andrew Mihal <acmihal@users.sourceforge.net>
159 January 27, 2007 enblend(1)