I am wondering how large an image PSP can handle and be able to use that 
various tools on the image without exceeding memory or causing the system to 
go to an error.

I want to have a 36" x 36" aerial photo scanned to a digital file.

But, I have had problems already on a much smaller photo. I scanned a 13" x 
13" photo in two pieces at 600 dpi which resulted in two 104MB .tif files. I 
was able to stitch these together with PSP only after changing them to .jpog 
with a compression of 15. My regular stitching program (autostitch) wouldnt 
process these files. So I use PSP and did the stitching by hand, but the 
result is an uneven color along the seam.

The resulting stiched together saved file was a 7,490 KB .jpg with 15 
compression.

That file is already large enough so that some of the PSP tools just wont 
work . . like rotation . . they go to PSP errors.

So, if 1 13x13 photo file of 7, 490 kB is hard to process with PSP, what 
hope is there to be able to load and use the scan of a 36x36 photo?

I want to be able to make versions of these documents of various sizes and 
be able to select sections of them to see minute detail and make separate 
images out of.

People must be able to scan these large photos ( commercial service) and 
process them somehow ( PSP or Photoshop or what?). But, how does one do 
this? 

rfr wrote:
> I am wondering how large an image PSP can handle and be able
> to use that various tools on the image without exceeding
> memory or causing the system to go to an error.
>
> I want to have a 36" x 36" aerial photo scanned to a digital
> file.
>
> But, I have had problems already on a much smaller photo. I
> scanned a 13" x 13" photo in two pieces at 600 dpi which
> resulted in two 104MB .tif files. I was able to stitch these
> together with PSP only after changing them to .jpog with a
> compression of 15. My regular stitching program (autostitch)
> wouldnt process these files. So I use PSP and did the
> stitching by hand, but the result is an uneven color along the
> seam.
>
> The resulting stiched together saved file was a 7,490 KB .jpg
> with 15 compression.
>
> That file is already large enough so that some of the PSP
> tools just wont work . . like rotation . . they go to PSP
> errors.
>
> So, if 1 13x13 photo file of 7, 490 kB is hard to process with
> PSP, what hope is there to be able to load and use the scan of
> a 36x36 photo?
>
> I want to be able to make versions of these documents of
> various sizes and be able to select sections of them to see
> minute detail and make separate images out of.
>
> People must be able to scan these large photos ( commercial
> service) and process them somehow ( PSP or Photoshop or
> what?). But, how does one do this?

PSP's limit on image size is 32,767 x 32,767 pixels. However, you 
are likely to run out of RAM and find processing unacceptably slow 
because of paging to the swap file long before that.

The size of the image file is irrelevant. Depending on compression, 
format, and options, it can be smaller or larger than the size of 
the image in memory.

The printed size of the image is also irrelevant. That depends on 
what your software tells the printer about how many pixels to print 
on each inch of paper, which we call the print resolution.

The only relevant measure of size within PSP is pixels. Most of what 
you wrote is therefore not of use in answering your questions. Your 
13" x 13" photo at 600 dpi, though, produces 7,800 x 7,800 pixels. 
That is large but not unusual for PSP.

How much memory will that photo take? If it's greyscale, count one 
byte per pixel for the background layer, two bytes per pixel for 
every other image layer, and one byte per pixel for each control 
layer (adjustment layer, mask, or selection). Add one or two more 
bytes per pixel for PSP's internal use.

Multiply that sum by the number of pixels in your image and compare 
with your RAM. Remember that XP wants about 250 MB and the PSP 
program wants about 70 MB.

Why are you scanning at 600 dpi? If you are scanning a negative, it 
is far too little; 4000 dpi would be more common. If you are 
scanning a print, it is far too much; 200 dpi recovers every detail 
in a print. At 200 dpi, your image will take 1/9 the memory it takes 
at 600 dpi.
-- 
Fred Hiltz,  fhiltz at yahoo dot com 

The 36x36 image is a printed photo. So was the 13x13 image.

I like to save my original scans in .tif files. These are usually very 
large. If I save them to .png files, those will always seem to be smaller. 
But, the tools to view images in XP and PSP work beeter with .tif than .png 
formats, so I have stayed with .tif format for the original saves.

I may be mistaken, but it seems to me that when I scan at 600dpi that I can 
do things with selected pieces that will reveal details that do not appear 
when I scan at, say 300 dpi. I am guesing that the extra pixels aid the 
histogram, or contrast tools or sharpening tools make quality decisions and 
other tools too.

There is some point reached where the added dpi doesnt yield any results to 
see revelaed and enhanced detail. I tried 1200dpi and that goes beyond 
managemable sizes for storage and also produces images so large they are at 
least sluggish to process with PSP or totally impossible.

Might Photoshop do a beter job processing large images? I heard that is has 
its own memory manager rather than relying on the operating system.

"Fred Hiltz" <not@home.ca> wrote in message 
news:I%vij.2649$ib7.443@trndny04...
> rfr wrote:
>> I am wondering how large an image PSP can handle and be able
>> to use that various tools on the image without exceeding
>> memory or causing the system to go to an error.
>>
>> I want to have a 36" x 36" aerial photo scanned to a digital
>> file.
>>
>> But, I have had problems already on a much smaller photo. I
>> scanned a 13" x 13" photo in two pieces at 600 dpi which
>> resulted in two 104MB .tif files. I was able to stitch these
>> together with PSP only after changing them to .jpog with a
>> compression of 15. My regular stitching program (autostitch)
>> wouldnt process these files. So I use PSP and did the
>> stitching by hand, but the result is an uneven color along the
>> seam.
>>
>> The resulting stiched together saved file was a 7,490 KB .jpg
>> with 15 compression.
>>
>> That file is already large enough so that some of the PSP
>> tools just wont work . . like rotation . . they go to PSP
>> errors.
>>
>> So, if 1 13x13 photo file of 7, 490 kB is hard to process with
>> PSP, what hope is there to be able to load and use the scan of
>> a 36x36 photo?
>>
>> I want to be able to make versions of these documents of
>> various sizes and be able to select sections of them to see
>> minute detail and make separate images out of.
>>
>> People must be able to scan these large photos ( commercial
>> service) and process them somehow ( PSP or Photoshop or
>> what?). But, how does one do this?
>
> PSP's limit on image size is 32,767 x 32,767 pixels. However, you
> are likely to run out of RAM and find processing unacceptably slow
> because of paging to the swap file long before that.
>
> The size of the image file is irrelevant. Depending on compression,
> format, and options, it can be smaller or larger than the size of
> the image in memory.
>
> The printed size of the image is also irrelevant. That depends on
> what your software tells the printer about how many pixels to print
> on each inch of paper, which we call the print resolution.
>
> The only relevant measure of size within PSP is pixels. Most of what
> you wrote is therefore not of use in answering your questions. Your
> 13" x 13" photo at 600 dpi, though, produces 7,800 x 7,800 pixels.
> That is large but not unusual for PSP.
>
> How much memory will that photo take? If it's greyscale, count one
> byte per pixel for the background layer, two bytes per pixel for
> every other image layer, and one byte per pixel for each control
> layer (adjustment layer, mask, or selection). Add one or two more
> bytes per pixel for PSP's internal use.
>
> Multiply that sum by the number of pixels in your image and compare
> with your RAM. Remember that XP wants about 250 MB and the PSP
> program wants about 70 MB.
>
> Why are you scanning at 600 dpi? If you are scanning a negative, it
> is far too little; 4000 dpi would be more common. If you are
> scanning a print, it is far too much; 200 dpi recovers every detail
> in a print. At 200 dpi, your image will take 1/9 the memory it takes
> at 600 dpi.
> -- 
> Fred Hiltz,  fhiltz at yahoo dot com
>
> 

rfr wrote:
> The 36x36 image is a printed photo. So was the 13x13 image.
>
> I like to save my original scans in .tif files. These are
> usually very large. If I save them to .png files, those will
> always seem to be smaller. But, the tools to view images in XP
> and PSP work beeter with .tif than .png formats, so I have
> stayed with .tif format for the original saves.

Sorry, but once PSP has opened the image, it does not matter what 
format it had on disk. All the lossless formats (TIF, PNG, PspImage) 
will preserve all the information. You can easily prove this for 
yourself by saving a test image in all three formats, opening those 
files, and using Image Arithmetic to compare them by subtraction, 
which will yield a pure black image RGB = 0, 0, 0.

> I may be mistaken, but it seems to me that when I scan at
> 600dpi that I can do things with selected pieces that will
> reveal details that do not appear when I scan at, say 300 dpi.
> I am guesing that the extra pixels aid the histogram, or
> contrast tools or sharpening tools make quality decisions and
> other tools too.

The very best enlarger, pro quality, and the very finest grain paper 
might store 250 pixels per inch, but I doubt you really have that 
detail here. True, some filters give better results with more 
pixels, which you can make by resizing an image in PSP just as well 
as by overscanning.

> There is some point reached where the added dpi doesnt yield
> any results to see revelaed and enhanced detail. I tried
> 1200dpi and that goes beyond managemable sizes for storage and
> also produces images so large they are at least sluggish to
> process with PSP or totally impossible.
>
> Might Photoshop do a beter job processing large images? I
> heard that is has its own memory manager rather than relying
> on the operating system.

Yes, Photoshop manages its own memory and does perform better with 
large images than PSP, especially when paging to disk is required.
-- 
Fred Hiltz,  fhiltz at yahoo dot com 

"Fred Hiltz" <not@home.ca> wrote in message 
news:Nozij.589$ac7.175@trndny03...
> rfr wrote:
>> The 36x36 image is a printed photo. So was the 13x13 image.
>>
>> I like to save my original scans in .tif files. These are
>> usually very large. If I save them to .png files, those will
>> always seem to be smaller. But, the tools to view images in XP
>> and PSP work beeter with .tif than .png formats, so I have
>> stayed with .tif format for the original saves.
>
It was the resulting files sizes between TIF, PNG and PSP that I noticed 
were radically different. I assumed there had to be some loss of detail 
somewhere to achieve the smaller file sizes.

> Sorry, but once PSP has opened the image, it does not matter what
> format it had on disk. All the lossless formats (TIF, PNG, PspImage)
> will preserve all the information. You can easily prove this for
> yourself by saving a test image in all three formats, opening those
> files, and using Image Arithmetic to compare them by subtraction,
> which will yield a pure black image RGB = 0, 0, 0.
>
I appreciate your sharing this with me as I would never have thought of 
this, having never used the Image Aritmetic feature ( never thought math on 
an Image was a useful concept). This use makes sense. I do like sluething 
methods . . and this will become one for me. Thank you!

>> I may be mistaken, but it seems to me that when I scan at
>> 600dpi that I can do things with selected pieces that will
>> reveal details that do not appear when I scan at, say 300 dpi.
>> I am guesing that the extra pixels aid the histogram, or
>> contrast tools or sharpening tools make quality decisions and
>> other tools too.
>
> The very best enlarger, pro quality, and the very finest grain paper
> might store 250 pixels per inch, but I doubt you really have that
> detail here. True, some filters give better results with more
> pixels, which you can make by resizing an image in PSP just as well
> as by overscanning.
>
You are saying that scanning beyond 300dpi is producing the same sort of 
"extra" pixels that you are saying is produced by simply increasing the size 
of the image within PSP. Hmmm. I will reexamine my ideas on this 600dpi 
idea.

>> There is some point reached where the added dpi doesnt yield
>> any results to see revelaed and enhanced detail. I tried
>> 1200dpi and that goes beyond managemable sizes for storage and
>> also produces images so large they are at least sluggish to
>> process with PSP or totally impossible.
>>
>> Might Photoshop do a beter job processing large images? I
>> heard that is has its own memory manager rather than relying
>> on the operating system.
>
> Yes, Photoshop manages its own memory and does perform better with
> large images than PSP, especially when paging to disk is required.
> -- 

At what file size should one chose to use Photoshop rather than PSP?

> Fred Hiltz,  fhiltz at yahoo dot com
>
> 

rfr wrote:
> "Fred Hiltz" <not@home.ca> wrote in message
> news:Nozij.589$ac7.175@trndny03...
[snip]
>> rfr wrote:
> It was the resulting files sizes between TIF, PNG and PSP that
> I noticed were radically different. I assumed there had to be
> some loss of detail somewhere to achieve the smaller file
> sizes.

They differ in the effectiveness of their lossless compression but 
all are indeed lossless. You may have been using uncompressed TIF. 
PNG is usually best for a single-layer (flattened) image, but only 
PspImage can store all the layers, text, vectors, etc. used by PSP.

[snip]
>>> Might Photoshop do a beter job processing large images? I
>>> heard that is has its own memory manager rather than relying
>>> on the operating system.
>>
>> Yes, Photoshop manages its own memory and does perform better
>> with large images than PSP, especially when paging to disk is
>> required. --
>
> At what file size should one chose to use Photoshop rather
> than PSP?

Remember, file size has nothing to do with this. It is the size in 
memory that counts. I told you how to find that from the size in 
pixels and the number of layers.

I have never heard a specific memory size where Photoshop is notably 
faster. I would guess that there is little difference as long as the 
image fits in RAM, but you could find someone who uses both products 
over at the Corel newsgroups (http://tinyurl.com/2pt9o) and get an 
informed answer.
-- 
Fred Hiltz,  fhiltz at yahoo dot com 

rfr wrote:


>
> Might Photoshop do a beter job processing large images? I heard that
> is has its own memory manager rather than relying on the operating
> system.

It might, but it is still using disk memory when it runs out of RAM, and 
it's that writing to disk instead of to RAM that's slowing things down. 
Depending on how much you have now, you will probably get the best speed up 
by adding more memory to your computer. Get as much as you can afford, and 
your motherboard and operating system can handle.
Also important is how your paging file is set up. It's usually best to let 
Windows control the size of the paging file. This can mean that as the size 
of paging file is increased and decreased that it becomes fragmented - 
broken up into several pieces. I once fixed a computer that had the paging 
file broken up into 475 pieces, and the performance increase after it was 
defragmented was amazing. Good defragmenting programs such as Raxco 
PerfectDisk can defrag the page file, as can the free PageDefrag at 
http://www.microsoft.com/technet/sysinternals/FileAndDisk/PageDefrag.mspx. 
Another way of preventing paging file fragmentation is to set a fixed size 
paging file, but that might cause problems if it isn't large enough to 
handle a very memory intensive task, such as editing a large image.


-- 
Tim