Sign in with
Sign up | Sign in
Your question

GT-30000

Last response: in Computer Peripherals
Share
Anonymous
October 19, 2004 6:35:04 PM

Archived from groups: alt.comp.periphs.scanner (More info?)

Hello,
i am using a Epson GT-30000, but have a little problem with it.
After scanning some lines it stops, drives back, and scans again. It works
fine, when i scan with 600dpi.
It is connected with a Adaptec 160MB/s SCSI card to a P4 with W2K.

Any ideas?

Regard,
Christian Schmitz

More about : 30000

Anonymous
October 19, 2004 6:35:05 PM

Archived from groups: alt.comp.periphs.scanner (More info?)

"Christian Schmitz" <hierbinich@t-online.de> wrote in message
news:cl31t5$jjv$04$1@news.t-online.com...
> Hello,
> i am using a Epson GT-30000, but have a little problem with it.
> After scanning some lines it stops, drives back, and scans again. It works
> fine, when i scan with 600dpi.
> It is connected with a Adaptec 160MB/s SCSI card to a P4 with W2K.
>
> Any ideas?
>
> Regard,
> Christian Schmitz
>
>
That may be normal. The size of the scan may effect the behavior. Try a
lower resolution.
The amount of ram installed in your computer will effect how the scanner
works.

--
CSM1
http://www.carlmcmillan.com
--
Anonymous
October 19, 2004 8:09:44 PM

Archived from groups: alt.comp.periphs.scanner (More info?)

> That may be normal. The size of the scan may effect the behavior. Try a
> lower resolution.
> The amount of ram installed in your computer will effect how the scanner
> works.
>

But I need a greater resolution, I have 2GB of RAM and using a
transfer-buffer of 16MB (more than the scanner can transmit within one
block).

Any better ideas?

Christian
Related resources
Can't find your answer ? Ask !
Anonymous
October 19, 2004 8:19:05 PM

Archived from groups: alt.comp.periphs.scanner (More info?)

"Christian Schmitz" <hierbinich@t-online.de> wrote in message
news:cl38o4$ph9$01$1@news.t-online.com...
>> That may be normal. The size of the scan may effect the behavior. Try a
>> lower resolution.
>> The amount of ram installed in your computer will effect how the scanner
>> works.
>>
>
> But I need a greater resolution, I have 2GB of RAM and using a
> transfer-buffer of 16MB (more than the scanner can transmit within one
> block).
>
> Any better ideas?
>
> Christian
>
>
From Epson Web site: Specs on GT-30000
http://www.epson.com/cgi-bin/Store/ProductQuickSpec.jsp...

Optical Resolution 600 dpi

Scanning Speed
600 dpi, Draft mode: Line-art: 0.39 msec/line (approx.), Grayscale:
0.39 msec/line (approx.), Full Color: 0.79 msec/line (approx.)

At 600 DPI, there are 6600 lines in a 11 inch scan.
So .79 ms times 6600 lines = 5214ms or 5.214 seconds.
It should take the scanner about 6 seconds to scan one page at 600 DPI in
color.

If it takes longer than that you have a bottleneck somewhere in the transfer
of the data from the scanner to the computer.

If you are trying to scan at higher that 600 DPI, you are forcing the
scanner to interpolate, which takes much longer and makes pixels out of
nothing.

It is a 600 DPI scanner. That is the maximum optical resolution of that
scanner.

--
CSM1
http://www.carlmcmillan.com
--
Anonymous
October 20, 2004 12:50:47 AM

Archived from groups: alt.comp.periphs.scanner (More info?)

> If it takes longer than that you have a bottleneck somewhere in the
transfer
> of the data from the scanner to the computer.
>
> If you are trying to scan at higher that 600 DPI, you are forcing the
> scanner to interpolate, which takes much longer and makes pixels out of
> nothing.

Mmmh, thats the question, is the bottleneck the scanner or the pc?
The scanner scans fine with 600 dpi, but at 500 dpi, 720 dpi, 300 dpi and so
on, it stops, drives back and scans again. But i can not imagine that the
interpolation is the problem.
At 600 dpi and running a stress tool, it is the same problem.
I think it has something to do with the scsi interface, but i am not sure.

> It is a 600 DPI scanner. That is the maximum optical resolution of that
> scanner.
>
Yes, the mainscain is 600dpi, but the subscan should be 1200dpi.

Christian
Anonymous
October 20, 2004 9:44:49 PM

Archived from groups: alt.comp.periphs.scanner (More info?)

"Christian Schmitz" <hierbinich@t-online.de> wrote in message
news:cl5osd$hft$00$1@news.t-online.com...
>> If it takes longer than that you have a bottleneck somewhere in the
> transfer
>> of the data from the scanner to the computer.
>>
>> If you are trying to scan at higher that 600 DPI, you are forcing the
>> scanner to interpolate, which takes much longer and makes pixels out of
>> nothing.
>
> Mmmh, thats the question, is the bottleneck the scanner or the pc?
> The scanner scans fine with 600 dpi, but at 500 dpi, 720 dpi, 300 dpi and
> so
> on, it stops, drives back and scans again. But i can not imagine that the
> interpolation is the problem.

But it is. Your choices should be 75, 100, 150, 200, 300, 400 and 600. Any
above 600 is interpolation.

> At 600 dpi and running a stress tool, it is the same problem.
> I think it has something to do with the scsi interface, but i am not sure.
>
>> It is a 600 DPI scanner. That is the maximum optical resolution of that
>> scanner.
>>
> Yes, the mainscain is 600dpi, but the subscan should be 1200dpi.
>
> Christian
>
>
NO, NO, The optical resolution of that scanner is 600 DPI. It says so in the
specification. 1200 DPI is for the stepping motor, that is the number of
steps the scanner can make down the sheet. The horizontal resolution is 600
DPI max.

Read Wayne Fulton's explanation.
http://www.scantips.com/chap3c.html

Your slow transfer (scan) may have something to do with the fact that those
resolutions are not even divisors of 600.

When the software has to reduce the data from the sensor, it mathematically
divides or multiplies the data by a scaling factor.

Do not go above 600, as 600 is the maximum resolution of the scanner without
interpolation. Then it really gets slow.

If you must scan at higher then 600 DPI, you have to get a new scanner with
higher resolution. There are some really low price scanners that will scan
flat documents at up to 3200 DPI. Most are around 1200 DPI.

1200 DPI Hp Scanjet 3670 for less than $80 at WalMart. I am not recommending
this scanner, I am using it for an example. Everybody in the USA has a
WalMart store nearby.
http://www.walmart.com/catalog/product.gsp?product_id=2...

At 600 DPI my scanner (Acer 620ST a 600 dpi SCSI), reads data, stops,
transfers to computer then continues the scan, it may stop and transfer
several times in one scan. The limit is the built-in buffer in the scanner.

I am using Windows XP Home with 512 MB ram on a 1.67 GHz AMD processor.

For your information, It takes the Acer 2 minutes and 42 seconds to scan a
8.5 X 11 inch color magazine cover at 600 DPI. The scanned image is 94.11
Megabytes.

Preview is 11 seconds at any resolution.

Off subject, What are you scanning that needs such a high resolution?
Art work should not need more that 600 DPI.

You can not get that kind of resolution out of ordinary paper and ink.

--
CSM1
http://www.carlmcmillan.com
--
Anonymous
October 22, 2004 12:03:02 AM

Archived from groups: alt.comp.periphs.scanner (More info?)

> NO, NO, The optical resolution of that scanner is 600 DPI. It says so in
the
> specification. 1200 DPI is for the stepping motor, that is the number of
> steps the scanner can make down the sheet. The horizontal resolution is
600
> DPI max.

Thats what i meant with Subscan, 600 dpi is the resolution of the ccd, 1200
dpi is the resolution of the stepper motor.

> Your slow transfer (scan) may have something to do with the fact that
those
> resolutions are not even divisors of 600.
>

I can not imagine, that this calculation will slow down the scanner, because
it does a lot of calculations even if it scans with 600 dpi.

> Do not go above 600, as 600 is the maximum resolution of the scanner
without
> interpolation. Then it really gets slow.
>
> If you must scan at higher then 600 DPI, you have to get a new scanner
with
> higher resolution. There are some really low price scanners that will scan
> flat documents at up to 3200 DPI. Most are around 1200 DPI.

Do you know a scanner with more the 600 dpi, that scans with 0.36ms/line?
That is what the GT-30000 does with 600 dpi.

A3:
Gray:
300 dpi: 2.2sec
600 dpi: 4.3sec
(1200 dpi: 34.4sec)
Color:
300 dpi: 4.4sec
600 dpi: 8.57sec
(1200 dpi: 101.7sec)

But i have made some further test and i am really sure, that the problem is
the SCSI-Interface.
Mainproblem is, that aquiring data from the scanner is done by a
real-time-priority-thread, this takes so much computing-power that copying
the data from the input buffer to the image buffer is not possible in the
remaining time.
Another problem is, even if you have 2GB, your OS (W2K in this case) would
not give you an area, that is great enough, so copying is done through the
swapfile with 12MB/s (PIV-Board Real-Mem-To-Mem-Copy is something around
500MB/s).
So, what i need, is a faster scsi-driver and a faster disk for swapping.

Ah, and... I do not want to print the images, it is for a
industrial-testing-system.

And, please forgive me, my worse english, ... still learning.


Christian
Anonymous
October 22, 2004 1:54:51 PM

Archived from groups: alt.comp.periphs.scanner (More info?)

On Thu, 21 Oct 2004 20:03:02 +0200 in alt.comp.periphs.scanner,
"Christian Schmitz" <hierbinich@t-online.de> wrote:

>> NO, NO, The optical resolution of that scanner is 600 DPI. It says so in
>the
>> specification. 1200 DPI is for the stepping motor, that is the number of
>> steps the scanner can make down the sheet. The horizontal resolution is
>600
>> DPI max.
>
>Thats what i meant with Subscan, 600 dpi is the resolution of the ccd, 1200
>dpi is the resolution of the stepper motor.
>
>> Your slow transfer (scan) may have something to do with the fact that
>those
>> resolutions are not even divisors of 600.
>>
>
>I can not imagine, that this calculation will slow down the scanner, because
>it does a lot of calculations even if it scans with 600 dpi.

The driver normally just passes the brightness/colour levels from the
scanner to the program, which writes them out to disk.
At abnormal resolutions, the driver or program has to look at
brightness/colour levels from four real pixels to calculate what it
should make up for the brightness/colour levels of the virtual pixels.
These kinds of operations should be left to image manipulation
programs, as those applications tend to do a better job than most
vendors' scanner drivers or interface programs, and often run code
customized for processor features like MMX, 3Dnow, etc. to work faster
as well as better.

>> Do not go above 600, as 600 is the maximum resolution of the scanner
>without
>> interpolation. Then it really gets slow.
>>
>> If you must scan at higher then 600 DPI, you have to get a new scanner
>with
>> higher resolution. There are some really low price scanners that will scan
>> flat documents at up to 3200 DPI. Most are around 1200 DPI.
>
>Do you know a scanner with more the 600 dpi, that scans with 0.36ms/line?
>That is what the GT-30000 does with 600 dpi.
>
>A3:
>Gray:
>300 dpi: 2.2sec
>600 dpi: 4.3sec
>(1200 dpi: 34.4sec)
twice as slow as the hardware would be (17s) due to
interpolation

>Color:
>300 dpi: 4.4sec
>600 dpi: 8.57sec
>(1200 dpi: 101.7sec)
three times as slow as the hardware would be (34s) due to
three colour interpolation

>But i have made some further test and i am really sure, that the problem is
>the SCSI-Interface.

Not likely, unless it is a faulty card or cable, and SCSI interfaces
tend to complain a lot about such things.
More likely just a slow driver doing generic math, perhaps using
software to avoids problems using the floating point unit.

>Mainproblem is, that aquiring data from the scanner is done by a
>real-time-priority-thread, this takes so much computing-power that copying
>the data from the input buffer to the image buffer is not possible in the
>remaining time.

The scanner waits for the go-ahead from the driver to step and scan.
And a SCSI interface requires the least CPU power of all interfaces.

>Another problem is, even if you have 2GB, your OS (W2K in this case) would
>not give you an area, that is great enough, so copying is done through the
>swapfile with 12MB/s (PIV-Board Real-Mem-To-Mem-Copy is something around
>500MB/s).

The system will give out the memory if asked for: that's why graphics
programs like gimp and PhotoShop need large memories and fast
processors.
Scanner programs normally just write chunks to disk as TIFF files.

>So, what i need, is a faster scsi-driver and a faster disk for swapping.
>
>Ah, and... I do not want to print the images, it is for a
>industrial-testing-system.

Do all your scanning at the maximum supported optical resolution:
600dpi. Then mess around in an image editing program; hints: results
are better if you keep dpi and sizes to small integer multiples or
dividers of the hardware values, rather than arbitrary values; and
save the image under a different name before you start fiddling with
it, so you can compare before and after appearance and quality, or
start again with the original scan.

--
Thanks. Take care, Brian Inglis Calgary, Alberta, Canada

Brian.Inglis@CSi.com (Brian[dot]Inglis{at}SystematicSW[dot]ab[dot]ca)
fake address use address above to reply
!