Photopaint X3 resampling problem?

OK.
Thanks Hunter.

HI Jeff:
OK but - if the image comes in at 72 dpi does this not affect the image resolution? I thought dpi represents the number of dot per square inch. So, less dots enlarged over a large area = poor quality when compared to a higher dpi setting?

My concern is that I wanted to provide an image size that could be easily emailed. So, 300 dpi is a  good setting for reproduction if the image was enlarged fro the original size. And each time I  opened it in Paint, the initial resample read 72 dpi before I do anything to it.

Build is version 13.0.0.739.
But I admit I find your comments educational Thank you.

SiMoN

wrote in message news:72564@coreldraw.com...
> HI Jeff:
> OK but - if the image comes in at 72 dpi does this not affect the image
> resolution? I thought dpi represents the number of dot per square inch.
> So, less dots enlarged over a large area = poor quality when compared to a
> higher dpi setting?
>
> My concern is that I wanted to provide an image size that could be easily
> emailed. So, 300 dpi is a good setting for reproduction if the image was
> enlarged fro the original size. And each time I opened it in Paint, the
> initial resample read 72 dpi before I do anything to it.
>
> Build is version 13.0.0.739.
> But I admit I find your comments educational Thank you.

Simon, you're confusing the physical size of the image in pixels with the
"resolution" - those are two totally separate things. Depending on what you
need to get to someone, emailing a file is not always a good option. Most
bitmap files already have some level of compression applied to them, so
using an application to "zip" them up will rarely reduce them in physical
size. A good bitmap for printing can sometimes be hundreds of megabytes in
size - get enough of them together and it's too big to email (that's why
most places want you to upload the files to their site as they may be too
big to email and too cumbersome to deal with in email from an organization
POV). Using email as your "limiter" to the file size of an image is not a
smart thing to do... unless you're talking about bitmaps that will only ever
be used/viewed on a computer monitor.

If I create a bitmap that is 300x300px, it doesn't matter one whit what the
"dpi" (which is an incorrect value - there are no "dots" in a bitmap as that
is a Printing term. There are only Pixels, which is why PPI is the correct
term, but unfortunately is rarely used in both applications and general
speeech. Many use the terms interchangeably which is not really a precise
thing to do) in the image reads. Regardless of whether this bitmap is set to
300ppi, 100ppi, 96, 72, or even 1ppi it doesn't change the fact that the
image is still 300x300px.

The physical display of a bitmap will vary from software app to software
app. Some applications will read in the PPI value and display the image
accordingly. Other apps couldn't care less what the PPI value is because
they'll only show the bitmap in its pure value of pixels. A web browser, for
example, doesn't read PPI info... in fact one of the original image formats
for the web (GIF) doesn't even hold PPI information in its file header. So a
100x100px image in a GIF, JPG, and/or PNG format would always show up as a
100x100px image even though the PPI in the GIF is technically zero, the JPG
could be 96ppi, the PNG could be 600ppi.

If you use pixels as your unit of measurement in Photopaint (which I do and
suggest people use as the default in that app) it will also just show you
the true physical size of the image. And that's the reason I suggest that
Pixels always be used as your default unit of measure in your bitmap
applications... let's say you have it set to Inches instead. You bring in a
file and it says that it's 3"x5". That really means nothing (at least to me)
because without knowing what the resolution is set to this 3x5 value could
be anything. If I view it with Pixels as my unit of measure, I will know
right away whether or not the physical dimensions of the image will actually
Print decently. (i.e., if the image comes in as something like 300x500px,
I'll know that this is waaaaaay too small to get a decent print... if it's
more like 600x1500px I know I'm dealing with a better image. And if it's
something like a 5000x3000px image I've got more to work with, as Jeff
mentioned, in terms of cropping/rotating/tweaking down to a smaller physical
size yet still retain enough pixels to produce a good print)

Does this help?

SimonKoy:

OK but - if the image comes in at 72 dpi does this not affect the image resolution? I thought dpi represents the number of dot per square inch. So, less dots enlarged over a large area = poor quality when compared to a higher dpi setting?

If you bring the 72 DPI image into Draw it will occupy a large physical space (from most cameras these days). Since...

4000 X 3000 pixels

at 72 DPI  =

55.556 " x  41.667 "

when you scale that image in any direction, the DPI changes

for example you scale it downwards proportionately to:

11" x 8.25"

it only means you compressed 4000 X 3000 pixels into a smaller physical area, increasing the pixels per inch (DPI)

Draw now shows 364 DPI in the status bar to correspond.

summary: no pixels were added or deleted. You still have 4000 X 3000 pixels.

SimonKoy:

My concern is that I wanted to provide an image size that could be easily emailed. So, 300 dpi is a  good setting for reproduction if the image was enlarged fro the original size. And each time I  opened it in Paint, the initial resample read 72 dpi before I do anything to it.

Generally, you can forget the DPI value. The artist at the other end will take your image and fit it into the space required.

If you're using highest-quality jpegs from your camera, the file size will likely be 5 MB or less. I'd just email it. It'll look huge in the email program, but it doesn't matter since the artist will know what to do with it. I hope. ;-)

If you really want to change the DPI in PP, resample the image but ensure the maintain original size box is checked in the resample dialog. Pixels will be unharmed. The DPI "header" info will be changed in the file if you save it into a format that retains it.

SimonKoy:

Now when I resample the same photographand save it as jpg2 or tiff, and open the file again in Photopaint, the resolution dpi reads correctly [not 72dpi] to the adjusted 300dpi. Save it as jpg open it again in Photopaint and resample

 

During your resampling process select a demension, for example I'm almost positive PP defaults to inches, set the physical size then the resolution, then save as and rename the file,  when the new saved file is reopened the resolution will be set to the phycisal size and have the proper settings.

Hi Hunter:
Yes I believe I am getting an understanding of what you are saying.

My focus if I understand correctly should really be my pixel size (ppi) not the resolution (dpi) since that can be increased or reduced without changing the ppi file size.
So let's say, if the image was shot at 300x500px  and I required it to be 5000x3000px in size for my purpose then this is where the the resampling is crucial. If the image is small , then resampling to high image size say 72dpi to 600dpi the quality may or will suffer. But if it already contains ppi information at a greater size and I am required to resample to a smaller size the quality will not be compromised.

Lesson learned would be to shoot everything RAW and adjust accordingly. Right?

I apologize to everyone here who has been very helpful regarding my ignorance. I will not hide the fact that I really do not know anything about this except what I have learned on my own and assistance from others.

Thank you.
SiMoN

wrote in message news:72708@coreldraw.com...
> Hi Hunter:
> Yes I believe I am getting an understanding of what you are saying.
>
> My focus if I understand correctly should really be my pixel size (ppi)
> not the resolution (dpi) since that can be increased or reduced without
> changing the ppi file size.
>

No, not exactly. "Pixel size", to me, would be the physical dimensions of
the image, say 3000x2000. PPI = pixels per inch. DPI = dots per inch. PPI
and/or DPI deal with "resolution" in terms of the image being printed. While
technically NOT the same thing, most people and software applications use
the terms interchangeably. They really have nothing to do with the true
physical dimension of the image, but how the printing device will interpret
those physical dimensions.


> So let's say, if the image was shot at 300x500px and I required it to be
> 5000x3000px in size for my purpose then this is where the the resampling
> is crucial. If the image is small , then resampling to high image size say
> 72dpi to 600dpi the quality may or will suffer. But if it already contains
> ppi information at a greater size and I am required to resample to a
> smaller size the quality will not be compromised.
>

??? An image would be "shot" at whatever the size is defined as in the
camera and no where else. A 300x500 image would be very small and not good
for printing, in my opinion. You *cannot* upscale a 300x500 image to a
3000x5000 image without really destroying the image. Why? Because you're
telling the computer to just "make up a whole bunch of pixels to fill up
this new sized image"... "Resampling" something small to something large
just doesn't work well (in general terms - there are apps some people use
for upsampling, but honestly that would require more experince than you have
right now to get it to look fair to average).

Think of a bitmap as a mosaic. It's just a bunch of pixels, which are just a
bunch of colored squares. Every pixel in a bitmap must have a "value" or
color assigned to it. So now think about that. Go get some graph paper, it's
all just a bunch of squares. Fill one square with some color. Now if you
wanted to "increase" the size of that square by 100% what are you going to
have to do? You're going to have to go color 3 additional squares around it
so you have another square. Ah, but in what direction do you make those
additional 3 squares? Well, you don't really have a choice in that with a
bitmap, your computer/application is going to make that decision for you.
And what if you have a photo that is 300x500 pixels and you want to upsample
it to something that is 3000x5000? That's a huge area, comparatively
speaking... the computer has to guess as to what colors to put into those
thousands upon thousands of extra pixels. You can't increase any detail
because there's nothing there to increase; the only data the computer has to
work with is whatever was in that small image.

Or think of it from a totally different point of view. You're going to go
hiking in the mountains. It's hot at the bottom of the valley, so you're
only wearing shorts and a t-shirt. You go hike up some 5000 to 9000 feet
above your current location... there are probably no trees at that point to
protect you from the wind, less atmosphere to retain heat, etc... and now
you're complaining that you're very cold and wish you'd worn longer pants
and a long-sleeved shirt. When I was a camp counselor and had kids who were
in this same situation I'd always have to say "you can always roll a
long-sleeved shirt up, but you can't roll a short-sleeved shirt down." It's
pretty much the same thing with bitmaps. You can always downsample a large
image to a small image and have pretty good quality... but you're not going
to get anything of quality in reverse.

So if your image is small to begin with and you need something larger, in
good quality, to go print... well, your only really good option is to go
reshoot the image. A 300x500 pixel image, at 300ppi/dpi would print at
3inches by 5 inches... a 3000x5000 pixel image at 300ppi/dpi would be able
to be printed at 10 inches by 16.5 inches fairly well... (depending on how
far back from the photo you plan to look at it, it could be printed larger
by just adjusting the ppi/dpi to something less than 300... i'd probably not
go less than 150, but that's just me... it all depends on what quality level
is satisfactory to you... and what will that level be? the only way to be
sure, is to print multiple versions at multiple ppi/dpi and/or pixel-sizes
and see what you like/don't like)

> Lesson learned would be to shoot everything RAW and adjust accordingly.
> Right?

Well, I always shoot in RAW, but that's just me. It is really not a matter
of shooting in RAW so much as it is shooting in the highest quality setting
your camera can do. I prefer to do the RAW and then do my own editing from
shot to shot, sometimes editing in both my RAW app and in Photopaint. Some
people don't like to do that level of "post-production" and prefer to shoot
JPG. Regardless of the file format you shoot in, you'll always get a better
quality image to work with when it's the largest size your camera can do as
opposed to any of the smaller sized images it can shoot. And excuses like
you don't have a large enough memory card to shoot bigger sized images is
not valid - you can get 8GB cards for $20 to $40 max. They're cheap enough
to buy a few to keep handy and rotate what you're using.

> I apologize to everyone here who has been very helpful regarding my
> ignorance. I will not hide the fact that I really do not know anything
> about this except what I have learned on my own and assistance from
> others.

no need to apologize, Simon - most of us have learned the same way. That's
what the newsgroups/forums are for.

Thanks Hunter;

I believe I got ti now.

wrote in message news:72723@coreldraw.com...
> Thanks Hunter;
>
> I believe I got ti now.

great - sometimes the concepts can be difficult to grasp on this stuff,
especially if you're used to the "rules" of vector images as opposed to
those of "raster" images (also if you're going from the concepts of Web
Imagery to Print Imagery - or vice-versa). And if you run into trouble
figuring something out (and that happens to ALL of us - I learn new stuff
about this all the time), just shout out to people here ... there's a huge
wealth of info among everyone.