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
25 Option mode selects the scan mode (Gray or Color).
26 Option depth determines the number of bits per sample (1. 8, or 16).
28 Keep in mind, that this value refers to the sample, not the pixel. So
29 depth=16 results in 48 bits per pixel in color mode. The most usual
30 combinations are mode=Gray, depth=1 for lineart, mode=Gray, depth=8 for
31 gray and mode=Color, depth=8 for color mode. The combination of color
32 and 1-bit mode is quite obscure (8 colors) but allowed in the SANE
33 standard. However, the meaning of bits is not defined. Currently 1 =
34 high intensity and 0 = low intensity is used.
35 Setting option hand-scanner results in the test-backend behaving like a
37 hand-scanner. Hand-scanners do not know the image height a priori.
38 Instead, they return a height of -1. Setting this option allows to
39 test whether a frontend can handle this correctly. This option also
40 enables a fixed width of 11 cm.
41 Setting option three-pass simulates a three-pass scanner. Older color
43 scanners needed to scan the image once per color (reg/green/blue) to
44 get the full image. Therefore, in this mode three single frames are
45 transmitted in color mode.
46 Option three-pass-order provides support for changing the order of the
48 three frames (see option three-pass above). A frontend should support
49 all orders.
50 Option resolution sets the resolution of the image in dots per inch.
52 Option source can be used to simulate an Automatic Document Feeder
54 (ADF). After 10 scans, the ADF will be "empty".
55
57 Option test-picture allows to set the image that's returned to the
58 frontend. While "Solid white" and "Solid black" are quite obvious, the
59 other options need some more explanation. Color patterns are used to
60 determine if all modes and their colors are represented correctly by
61 the frontend. The grid should look like the same in every mode and
62 resolution. A table of all the test pictures can be found at:
63 http://www.meier-geinitz.de/sane/test-backend/test-pictures.html.
64 If option invert-endianess is set, the upper and lower bytes of image
66 data in 16 bit modes are exchanged. This option can be used to test
67 the 16 bit modes of frontends, e.g. if the frontend uses the correct
68 endianess.
69 If option read-limit is set, the maximum amount of data transferred
71 with each call to sane_read() is limited.
72 Option read-limit-size sets the limit for option read-limit. A low
74 limit slows down scanning. It can be used to detect errors in frontend
75 that occur because of wrong assumptions on the size of the buffer or
76 timing problems.
77 Option read-delay enables delaying data to the frontend.
79 Option read-delay-duration selects the number of microseconds the back‐
81 ends waits after each transfer of a buffer. This option is useful to
82 find timing-related bugs, especially if used over the network.
83 If option read-return-value is different from "Default", the selected
85 status will be returned by every call to sane_read(). This is useful
86 to test the frontend's handling of the SANE statii.
87 If option ppl-loss is different from 0, it determines the number of
89 pixels that are "lost" at the end of each line. That means, lines are
90 padded with unused data.
91 Option fuzzy-parameters selects that fuzzy (inexact) parameters are
93 returned as long as the scan hasn't been started. This option can be
94 used to test if the frontend uses the parameters it got before the
95 start of the scan (which it shouldn't).
96 Option non-blocking determines if non-blocking IO for sane_read()
98 should be used if supported by the frontend.
99 If option select-fd is set, the backend offers a select filedescriptor
101 for detecting if sane_read() will return data.
102 If option enable-test-options is set, a fairly big list of options for
104 testing the various SANE option types is enabled.
105 Option print-options can be used to print a list of all options to
107 standard error.
108
110 Option tl-x determines the top-left x position of the scan area.
111 Option tl-y determines the top-left y position of the scan area.
113 Option br-x determines the bottom-right x position of the scan area.
115 Option br-y determines the bottom-right y position of the scan area.
117
119 There are 6 bool test options in total. Each option is numbered.
120 (3/6) means: this is option 3 of 6. The numbering scheme is intended
121 for easier detection of options not displayed by the frontend (because
122 of missing support or bugs).
123 Option bool-soft-select-soft-detect (1/6) is a bool test option that
125 has soft select and soft detect (and advanced) capabilities. That's
126 just a normal bool option.
127 Option bool-hard-select-soft-detect (2/6) is a bool test option that
129 has hard select and soft detect (and advanced) capabilities. That
130 means the option can't be set by the frontend but by the user (e.g. by
131 pressing a button at the device).
132 Option bool-hard-select (3/6) is a bool test option that has hard
134 select (and advanced) capabilities. That means the option can't be set
135 by the frontend but by the user (e.g. by pressing a button at the
136 device) and can't be read by the frontend.
137 Option bool-soft-detect (4/6) is a bool test option that has soft
139 detect (and advanced) capabilities. That means the option is read-
140 only.
141 Option bool-soft-select-soft-detect-emulated (5/6) is a Bool test
143 option that has soft select, soft detect, and emulated (and advanced)
144 capabilities.
145 Option bool-soft-select-soft-detect-auto (6/6) is a Bool test option
147 that has soft select, soft detect, and automatic (and advanced) capa‐
148 bilities. This option can be automatically set by the backend.
149
151 There are 6 int test options in total.
152 Option int (1/6) is an int test option with no unit and no constraint
154 set.
155 Option int-constraint-range (2/6) is an int test option with unit pixel
157 and constraint range set. Minimum is 4, maximum 192, and quant is 2.
158 Option int-constraint-word-list (3/6) is an int test option with unit
160 bits and constraint word list set.
161 Option int-constraint-array (4/6) is an int test option with unit mm
163 and using an array without constraints.
164 Option int-constraint-array-constraint-range (5/6) is an int test
166 option with unit mm and using an array with a range constraint. Mini‐
167 mum is 4, maximum 192, and quant is 2.
168 Option int-constraint-array-constraint-word-list (6/6) is an int test
170 option with unit percent and using an array a word list constraint.
171
174 There are 3 fixed test options in total.
175 Option fixed (1/3) is a fixed test option with no unit and no con‐
177 straint set.
178 Option fixed-constraint-range (2/3) is a fixed test option with unit
180 microsecond and constraint range set. Minimum is -42.17, maximum
181 32767.9999, and quant is 2.0.
182 Option fixed-constraint-word-list (3/3) is a Fixed test option with no
184 unit and constraint word list set.
185
187 There are 3 string test options in total.
188 Option string (1/3) is a string test option without constraint.
190 Option string-constraint-string-list (2/3) is a string test option with
192 string list constraint.
193 Option string-constraint-long-string-list (3/3) is a string test option
195 with string list constraint. Contains some more entries...
196
198 Option button (1/1) is a Button test option. Prints some text...
199
201 /etc/sane.d/test.conf
202 The backend configuration file (see also description of
203 SANE_CONFIG_DIR below). The initial values of most of the basic
204 SANE options can be configured in this file. A template contain‐
205 ing all the default values is provided together with this back‐
206 end. One of the more interesting values may be num‐
207 ber_of_devices. It can be used to check the frontend's ability
208 to show a long list of devices. The config values concerning
209 resolution and geometry can be useful to test the handling of
210 big file sizes.
211 /usr/lib*/sane/libsane-test.a
214 The static library implementing this backend.
215 /usr/lib*/sane/libsane-test.so
217 The shared library implementing this backend (present on systems
218 that support dynamic loading).
219
221 SANE_CONFIG_DIR
222 This environment variable specifies the list of directories that
223 may contain the configuration file. Under UNIX, the directories
224 are separated by a colon (`:'), under OS/2, they are separated
225 by a semi-colon (`;'). If this variable is not set, the config‐
226 uration file is searched in two default directories: first, the
227 current working directory (".") and then in /etc/sane.d. If the
228 value of the environment variable ends with the directory sepa‐
229 rator character, then the default directories are searched after
230 the explicitly specified directories. For example, setting
231 SANE_CONFIG_DIR to "/tmp/config:" would result in directories
232 "tmp/config", ".", and "/etc/sane.d" being searched (in this
233 order).
234 SANE_DEBUG_TEST
236 If the library was compiled with debug support enabled, this
237 environment variable controls the debug level for this backend.
238 Higher debug levels increase the verbosity of the output.
239 Example: export SANE_DEBUG_TEST=4
241
244 sane(7), http://www.meier-geinitz.de/sane/test-backend/
245
249 Henning Meier-Geinitz <henning@meier-geinitz.de>
250
253 - config file values aren't tested for correctness
254sane-backends 1.0.18 2 Jan 2006 sane-test(5)