Black square

[Jiri Stary]

Hi, i have a problem with jsane. When i try to scan a page i recieve only a black page. I am using sane backend 0.20 and scanning from xsane remotely or using device software works ok. When I debug saned I noticed that device I/O error is reported and scanning is halted immediately, only about 9 bytes of data are send. Is there any change getting this fixed ?

[Andi McLean]

Are you setting the x and y offset and size to scan options? (The default depend on the backend)

when you call:
frame = device.getFrame()

change to
JSane_Wire.showInput = true;
JSane_Wire.showOutput = true;
frame=device.getFrame();
JSane_Wire.showInput = false;
JSane_Wire.showOutput = false;

That will display what JSane is sending over the connection.
Can you post the results?

Andi

[Jiri Stary]

yes I am, I use follwoing settings:

           device.getOption("resolution").setValue("75");
   device.getOption("mode").setValue("Color - 16 Million Colors");
   device.getOption("page-format").setValue("A4 - 210x297 mm");
   device.getOption("tl-x").setValue("0");
           device.getOption("tl-y").setValue("0");
           device.getOption("br-x").setValue("210");
   device.getOption("br-y").setValue("297");

The Output you requested is:

<pre><code>
Out 0 /Out 0 /Out 0 /Out 7 /Word Out = 7
Out 0 /Out 0 /Out 0 /Out 0 /Word Out = 0
In 0 /In 0 /In 0 /In 0 /Word In = 0
In 0 /In 0 /In 222 /In 88 /Word In = 56920
In 0 /In 0 /In 18 /In 52 /Word In = 4660
In 0 /In 0 /In 0 /In 0 /Word In = 0
Getting String
Out 0 /Out 0 /Out 0 /Out 6 /Word Out = 6
Out 0 /Out 0 /Out 0 /Out 0 /Word Out = 0
In 0 /In 0 /In 0 /In 0 /Word In = 0
In 0 /In 0 /In 0 /In 1 /Word In = 1
In 0 /In 0 /In 0 /In 1 /Word In = 1
In 0 /In 0 /In 7 /In 62 /Word In = 1854
In 0 /In 0 /In 2 /In 106 /Word In = 618
In 0 /In 0 /In 3 /In 108 /Word In = 876
In 0 /In 0 /In 0 /In 8 /Word In = 8
In 255 /In 255 /In 255 /In 255 /Word In = -1
</code></pre>

This is debug from saned -d128

<pre><code>
stary@krusovice:/usr/bin$ saned -d128
main: starting debug mode (level 128)
read_config: searching for config file
read_config: done reading config
saned (AF-indep+IPv6) from sane-backends 1.0.20 starting up
do_bindings: trying to get port for service "sane-port" (getaddrinfo)
do_bindings:  socket () using IPv6
do_bindings:  setsockopt ()
do_bindings:  bind () to port 6566
do_bindings:  listen ()
do_bindings:  socket () using IPv4
do_bindings:  setsockopt ()
do_bindings:  bind () to port 6566
do_bindings:  bind failed: Address already in use
run_standalone: spawning Avahi process
run_standalone: waiting for control connection
saned_avahi_callback: AVAHI_CLIENT_S_RUNNING
saned_create_avahi_services: adding service 'saned'
saned_avahi_group_callback: service 'saned' successfully established
handle_connection: processing client connection
check_host: detected an IPv4-mapped address
check_host: access by remote host: ::ffff:127.0.0.1
check_host: remote host is IN_LOOPBACK: access granted
init: access granted
init: access granted to stary@::ffff:127.0.0.1
process_request: waiting for request
process_request: got request 1
process_request: waiting for request
process_request: got request 2
process_request: access to resource `smfp' granted
process_request: sane_open returned: Success
process_request: waiting for request
process_request: got request 4
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 5
process_request: waiting for request
process_request: got request 7
start_scan: trying to bind data port 0
start_scan: using port 56920 for data
process_request: waiting for data connection
process_request: access to data port from ::ffff:127.0.0.1
do_scan: start
do_scan: trying to read 8188 bytes from scanner
do_scan: read 0 bytes from scanner
do_scan: status = `Error during device I/O'
do_scan: statuscode `Error during device I/O' was added to buffer
do_scan: trying to write 9 bytes to client
do_scan: wrote 9 bytes to client
do_scan: processing RPC request on fd 4
process_request: waiting for request
process_request: got request 6
do_scan: done, status=Error during device I/O
process_request: waiting for request
process_request: got request 3
process_request: waiting for request
process_request: got request 10
bailing out, waiting for children…
bail_out: all children exited
stary@krusovice:/usr/bin$
</code></pre>

[Andi McLean]

I think there might be a problem with the following lines of code:

<pre><code>
device.getOption("mode").setValue("Color - 16 Million Colors");
device.getOption("page-format").setValue("A4 - 210x297 mm");
</code></pre>

If you use the Tester.java program found under JSane_Frontends, it should show you the options available and values you can use.

[Jiri Stary]

I downloaded the jar file with frontend and it threw exception, howerer if i scan scanner options with this code the vaules seems correct:
<pre><code>
  int options = device.getNumberOptions();

   for (int loop = 0; loop < options; ++loop)
   {
       JSane_Base_Option_Type_Descriptor option = device.getOption(loop);
       System.out.println(option);
       if (!( option.getValueType()  instanceof JSane_Base_Type_Group )
       && device.getOption(loop).toString().length() > 15 ) //otherwise i get null pointer
       {
    System.out.println("Name: " +device.getOption(loop).getName());
   
      
       System.out.println(device.getOption(loop).getValue());
       }
   }
</code></pre>

<pre><code>
Option - 3 mode Sets the color composition mode of the scanned image
Black and White - Line Art
Grayscale - 256 Levels
Color - 16 Million Colors

……

Option - 6 page-format Sets the paper format of the scanned page
A4 - 210x297 mm
Letter - 8.5"x11"
Statement - 5.5"x8.5"
Executive - 7.25"x10.5"
A5 - 148x210 mm
B5 - 176x250 mm
B5 (JIS) - 182x257 mm
Quarto - 215x275 mm
Envelope #9 - 3.875"x8.875"
Envelope #10 - 4.125"x9.5"
Envelope #11 - 4.5"x10.375"
Envelope #12 - 4"x11"
Envelope #14 - 5"x11.5"
Envelope DL - 110x220 mm
Envelope C5 - 162x229 mm
Envelope C6 - 114x162 mm
Envelope C6/C5 - 114x229 mm
Envelope B5 - 176x250 mm
Envelope B6 - 125x176 mm
Envelope - 110x230 mm
Envelope Monarch - 3.875"x7.5"
A5 Extra - 174x235 mm
B5 (ISO) Extra - 201x276 mm
Custom
</code></pre>

The values I used are the default ones and if i ommit them the result is the same

[Jiri Stary]

I have a new info. If  I keep the connection alive, the first attempt to scan fails returning a black square but the second attempt is succesful.

[Anonymous]

I am getting the same black square. A try to scan with two attemps and the second was succeful.

I think it is a connection problem between API and saned. Do you get any solution this issue?

[Andi McLean]

Is it just a black square on the image or is the whole image black?

Do you get the same results when using XSane , scanimage?

[Anonymous]

I 'll try with scanimage tomorrow. Here I have only a hp scanners and all is working fine. With SAMSUNG (SCX4521) scanner i got the black square (whole image).
Using XSane image scanner (Ubuntu 9.10 distro) the scanner works ok too.
But when i use java api, black square.
When I do the following code:
device.open();
JSane_Base_Frame frame = device.getFrame();
// Get the image from frame
BufferedImage image = frame.getImage(false);
device.close();
device.open();
… the rest of the options …
//device.open();
frame = device.getFrame();
// Get the image from frame
image = frame.getImage(false);
device.close();
connection.exit();

---

The scan works OK.

It appears to be a connection problem. I Tried to run the Morena Studio Applet and i've got almost the same error (null pointer).

[Anonymous]

Another info:

When we are at the first scan atempt, the  !_param.lastFrame return true.

[Andi McLean]

Can you run saned from the command line with debug turned on

saned -d128