This reverts commit 0a6a06346a.
The commit replaced the text to search for from ALICE to BOB, because
our OCR detection only caught "BOB FOOBAR" but missed "ALICE FOOBAR"
completely.
With the improvements to our OCR system this no longer is the case and
the test passes successfully with this reverted.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Cc: @shlevy
First of all, we're now using ImageMagick to improve the screenshot so
that Tesseract has an esier time to recognize the text. The resulting
image of this post-processing is a scaled up black-and-white version
with the backgrounds almost entirely removed and the text edges a bit
blurred, so the screen shots now more or less resemble an image from a
scanner rather. This is what Tesseract is trained for by default.
As mentioned in the previous commit we now also use Tesseract 4, which
further improves the quality of text recognition.
I've spent countless hours just to test different postprocessing
variants and testing what works best for our tests and this is the one
that worked best so far. It's certainly not perfect and I'd like to
avoid the scaling step but we're way better off than before.
In addition to this, the OCR process is now done without an intermediate
file, solely using pipes.
I've tested this using the following VM tests which have OCR enabled:
* nixos/tests/chromium.nix -A stable
* nixos/tests/emacs-daemon.nix
* nixos/tests/installer.nix -A luksroot
* nixos/tests/lightdm.nix
* nixos/tests/plasma5.nix
* nixos/tests/sddm.nix
All of the tests still succeed and comparing some of the recognition
results to the earlier results it now also detects a lot more text than
before this commit.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
I've removed that attribute in 68bc260ca2,
because the language files no longer were distributed as seperate files,
but if we for example only want to use the English training data, the
closure size of Tesseract gets quite large (around 1.2 GB), which is a
bit much just to be able to run NixOS VM tests.
For this reason I've also switched the VM tests back to using only the
English language.
Tested using the following VM tests (the ones that have OCR enabled) on
x86_64-linux:
* nixos/tests/chromium.nix -A stable
* nixos/tests/emacs-daemon.nix
* nixos/tests/installer.nix -A luksroot
* nixos/tests/lightdm.nix
* nixos/tests/plasma5.nix
* nixos/tests/sddm.nix
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
gyre-fonts provides high-quality TrueType substitutes for standard PostScript
fonts. Unlike most other distributions, NixOS does not install Ghostscript and
its Type 1 fonts by default, so we must get the standard fonts elsewhere.
For whatever reason, the OCR code is not detecting ALICE but is BOB.
OCR output from login screen (blank lines omitted):
> Session none + icewm
> 08:41 <
> Thursday, April 6, 2017
> BOB FOOBAR
> Select your user and enter password
The LUKS header can be on another device (e.g. a USB stick). In my case
it can take up to two seconds until the partition on my USB stick is
available (i.e. the decryption fails without this patch). This will also
remove some redundancy by providing the shell function `wait_target` and
slightly improve the output (one "." per second and a success/failure
indication after 10 seconds instead of always printing "ok").
Restarting them is useless since the filesystem is already
checked. Worse, restarting them causes the filesystem to be unmounted.
Also remove an override for systemd-rkill@.service which no longer
exists.
This reduces the time window during which IP addresses are gone during
switch-to-configuration. A complication is that with stopIfChanged =
true, preStop would try to delete the *new* IP addresses rather than
the old one (since the preStop script now runs after the switch to the
new configuration). So we now record the actually configured addresses
in /run/nixos/network/addresses/<interface>. This is more robust in
any case.
Issue https://github.com/NixOS/nixops/issues/640.
Unfortunately, somewhere between 16.09 and 17.03, paravirtualized
instances stopped working. They hang at the pv-grub prompt
("grubdom>"). I tried reverting to a 4.4 kernel, reverting kernel
compression from xz to bzip2 (even though pv-grub is supposed to
support xz), and reverting the only change to initrd generation
(5a8147479e). Nothing worked so I'm
giving up.
