1sane-test(5) SANE Scanner Access Now Easy sane-test(5)
2
6 sane-test - SANE backend for testing frontends
7
9 The sane-test library implements a SANE (Scanner Access Now Easy) back‐
10 end that allows testing the SANE installation and SANE frontends. It
11 provides access to a (nearly) unlimited number of virtual devices.
12 There is no support for real scanners or cameras. However, the backend
13 simulates scanning and setting options.
14 The idea is not only to find bugs in frontends but also to show all
16 capabilities of SANE. Therefore sane-test implements functions and
17 options that are not (or seldom) found in other backends.
18 The backend is commented out in /etc/sane.d/dll.conf, so either the
20 comment character must be removed or the backend must be called explic‐
21 itly. E.g. scanimage -d test or xscanimage test.
22
26 Option mode selects the scan mode (Gray or Color).
27 Option depth determines the number of bits per sample (1. 8, or 16).
29 Keep in mind, that this value refers to the sample, not the pixel. So
30 depth=16 results in 48 bits per pixel in color mode. The most usual
31 combinations are mode=Gray, depth=1 for lineart, mode=Gray, depth=8 for
32 gray and mode=Color, depth=8 for color mode. The combination of color
33 and 1-bit mode is quite obscure (8 colors) but allowed in the SANE
34 standard. However, the meaning of bits is not defined. Currently 1 =
35 high intensity and 0 = low intensity is used.
36 Setting option hand-scanner results in the test-backend behaving like a
38 hand-scanner. Hand-scanners do not know the image height a priori.
39 Instead, they return a height of -1. Setting this option allows one to
40 test whether a frontend can handle this correctly. This option also
41 enables a fixed width of 11 cm.
42 Setting option three-pass simulates a three-pass scanner. Older color
44 scanners needed to scan the image once per color (reg/green/blue) to
45 get the full image. Therefore, in this mode three single frames are
46 transmitted in color mode.
47 Option three-pass-order provides support for changing the order of the
49 three frames (see option three-pass above). A frontend should support
50 all orders.
51 Option resolution sets the resolution of the image in dots per inch.
53 Option source can be used to simulate an Automatic Document Feeder
55 (ADF). After 10 scans, the ADF will be "empty".
56
58 Option test-picture allows one to set the image that's returned to the
59 frontend. While "Solid white" and "Solid black" are quite obvious, the
60 other options need some more explanation. Color patterns are used to
61 determine if all modes and their colors are represented correctly by
62 the frontend. The grid should look like the same in every mode and
63 resolution. A table of all the test pictures can be found at:
64 http://www.meier-geinitz.de/sane/test-backend/test-pictures.html.
65 If option invert-endianness is set, the upper and lower bytes of image
67 data in 16 bit modes are exchanged. This option can be used to test
68 the 16 bit modes of frontends, e.g. if the frontend uses the correct
69 endianness.
70 If option read-limit is set, the maximum amount of data transferred
72 with each call to sane_read() is limited.
73 Option read-limit-size sets the limit for option read-limit. A low
75 limit slows down scanning. It can be used to detect errors in frontend
76 that occur because of wrong assumptions on the size of the buffer or
77 timing problems.
78 Option read-delay enables delaying data to the frontend.
80 Option read-delay-duration selects the number of microseconds the back‐
82 ends waits after each transfer of a buffer. This option is useful to
83 find timing-related bugs, especially if used over the network.
84 If option read-return-value is different from "Default", the selected
86 status will be returned by every call to sane_read(). This is useful
87 to test the frontend's handling of the SANE statuses.
88 If option ppl-loss is different from 0, it determines the number of
90 pixels that are "lost" at the end of each line. That means, lines are
91 padded with unused data.
92 Option fuzzy-parameters selects that fuzzy (inexact) parameters are
94 returned as long as the scan hasn't been started. This option can be
95 used to test if the frontend uses the parameters it got before the
96 start of the scan (which it shouldn't).
97 Option non-blocking determines if non-blocking IO for sane_read()
99 should be used if supported by the frontend.
100 If option select-fd is set, the backend offers a select filedescriptor
102 for detecting if sane_read() will return data.
103 If option enable-test-options is set, a fairly big list of options for
105 testing the various SANE option types is enabled.
106 Option print-options can be used to print a list of all options to
108 standard error.
109
111 Option tl-x determines the top-left x position of the scan area.
112 Option tl-y determines the top-left y position of the scan area.
114 Option br-x determines the bottom-right x position of the scan area.
116 Option br-y determines the bottom-right y position of the scan area.
118
120 There are 6 bool test options in total. Each option is numbered.
121 (3/6) means: this is option 3 of 6. The numbering scheme is intended
122 for easier detection of options not displayed by the frontend (because
123 of missing support or bugs).
124 Option bool-soft-select-soft-detect (1/6) is a bool test option that
126 has soft select and soft detect (and advanced) capabilities. That's
127 just a normal bool option.
128 Option bool-hard-select-soft-detect (2/6) is a bool test option that
130 has hard select and soft detect (and advanced) capabilities. That
131 means the option can't be set by the frontend but by the user (e.g. by
132 pressing a button at the device).
133 Option bool-hard-select (3/6) is a bool test option that has hard
135 select (and advanced) capabilities. That means the option can't be set
136 by the frontend but by the user (e.g. by pressing a button at the
137 device) and can't be read by the frontend.
138 Option bool-soft-detect (4/6) is a bool test option that has soft
140 detect (and advanced) capabilities. That means the option is read-
141 only.
142 Option bool-soft-select-soft-detect-emulated (5/6) is a Bool test
144 option that has soft select, soft detect, and emulated (and advanced)
145 capabilities.
146 Option bool-soft-select-soft-detect-auto (6/6) is a Bool test option
148 that has soft select, soft detect, and automatic (and advanced) capa‐
149 bilities. This option can be automatically set by the backend.
150
152 There are 6 int test options in total.
153 Option int (1/6) is an int test option with no unit and no constraint
155 set.
156 Option int-constraint-range (2/6) is an int test option with unit pixel
158 and constraint range set. Minimum is 4, maximum 192, and quant is 2.
159 Option int-constraint-word-list (3/6) is an int test option with unit
161 bits and constraint word list set.
162 Option int-constraint-array (4/6) is an int test option with unit mm
164 and using an array without constraints.
165 Option int-constraint-array-constraint-range (5/6) is an int test
167 option with unit mm and using an array with a range constraint. Mini‐
168 mum is 4, maximum 192, and quant is 2.
169 Option int-constraint-array-constraint-word-list (6/6) is an int test
171 option with unit percent and using an array a word list constraint.
172
175 There are 3 fixed test options in total.
176 Option fixed (1/3) is a fixed test option with no unit and no con‐
178 straint set.
179 Option fixed-constraint-range (2/3) is a fixed test option with unit
181 microsecond and constraint range set. Minimum is -42.17, maximum
182 32767.9999, and quant is 2.0.
183 Option fixed-constraint-word-list (3/3) is a Fixed test option with no
185 unit and constraint word list set.
186
188 There are 3 string test options in total.
189 Option string (1/3) is a string test option without constraint.
191 Option string-constraint-string-list (2/3) is a string test option with
193 string list constraint.
194 Option string-constraint-long-string-list (3/3) is a string test option
196 with string list constraint. Contains some more entries...
197
199 Option button (1/1) is a Button test option. Prints some text...
200
202 /etc/sane.d/test.conf
203 The backend configuration file (see also description of
204 SANE_CONFIG_DIR below). The initial values of most of the basic
205 SANE options can be configured in this file. A template contain‐
206 ing all the default values is provided together with this back‐
207 end. One of the more interesting values may be num‐
208 ber_of_devices. It can be used to check the frontend's ability
209 to show a long list of devices. The config values concerning
210 resolution and geometry can be useful to test the handling of
211 big file sizes.
212 /usr/lib64/sane/libsane-test.a
215 The static library implementing this backend.
216 /usr/lib64/sane/libsane-test.so
218 The shared library implementing this backend (present on systems
219 that support dynamic loading).
220
223 SANE_CONFIG_DIR
224 This environment variable specifies the list of directories that
225 may contain the configuration file. Under UNIX, the directories
226 are separated by a colon (`:'), under OS/2, they are separated
227 by a semi-colon (`;'). If this variable is not set, the config‐
228 uration file is searched in two default directories: first, the
229 current working directory (".") and then in /etc/sane.d. If the
230 value of the environment variable ends with the directory sepa‐
231 rator character, then the default directories are searched after
232 the explicitly specified directories. For example, setting
233 SANE_CONFIG_DIR to "/tmp/config:" would result in directories
234 tmp/config, ., and /etc/sane.d being searched (in this order).
235 SANE_DEBUG_TEST
237 If the library was compiled with debug support enabled, this
238 environment variable controls the debug level for this backend.
239 Higher debug levels increase the verbosity of the output.
240 Example: export SANE_DEBUG_TEST=4
242
245 sane(7), scanimage(1), xscanimage(1)
246 http://www.meier-geinitz.de/sane/test-backend/
247
251 Henning Meier-Geinitz <henning@meier-geinitz.de>
252
255 - config file values aren't tested for correctness
256 14 Jul 2008 sane-test(5)