Re: Text overlay on image then Save to JPEG with reasonable DPI for Online printshop

"Rob" <robnews@xxxxxxxxxx> wrote in message
news:43832a6e$0$11068$e4fe514c@xxxxxxxxxxxxxxxxx

> So reading 'till so far, it's pssible to show the user a smaller
> image. But I like the application to show the final output.
> And the final output is, for the user, the postcard-format
> photo from the photshop. This measures 14 X 9 CM so
> the viewable part should be, in my opinion, 14 X 9 CM.

Hi again Rob. Before we go any further I think it's about time we put this
"size" thing to bed! I don't want you to think that I'm just "waffling on"
about the same thing all the time for no apparent reason, but it really is
*very important* that you get your head around it. First have a look back at
my quite long recent answer (the one in which I "waffled on" for ages about
"pixels" and "logical centimetres" and "pretend units of measurement" and
stuff like that). Read it all again . . .

.. . . okay. Now that you've read it again I'll expand on it a little. The
first thing I want to say is that it is *impossible* for you or for anyone
else to write a VB program (or any other program for that matter) in which
you can draw a 14 x 9 centimetre rectangle on the screen and guarantee that
it actually measures 14 x 9 centimetres when the user holds a ruler up
against the screen. There are various reasons for this which I won't go into
right now in order to avoid over complicating the issue, but if you really
want to know what they are then post again and I'll explain it to you (but
it will be a lot for you to read!). To see what I mean, open up a program
that you trust (Microsoft Publisher or Microsoft Word or Corel Draw or
whatever) and place a rectangle on the displayed page. Use whatever menus
are available to set the size of the rectangle to exactly 10 x 10
centimetres. Now use the "view" menu (or whatever it is called in the
application you are using) and set toh view to "100%" or "actual size" or
whatever terminology that application uses to signify that the page and its
objects should be displayed at "actual size". Now hold a standard ruler up
against the display and measure the size of the rectangle. You will almost
certainly find it to be somethinf different than 10 x 10 centimetres, and if
you try exactly the same thing on many different computers you will probably
find that it is a different actual size on all of them! In fact, you will
probably find that it isn't even square! That is simply "how things are" in
this world, and there is nothing you can do about it!

Printers, however, are a completely different things. They are nbot at all
like monitors. All printers (inkjet, lazer, etc) also use "logical units of
measurement". The difference is that with printers the "logical units" are
almost always *exactly* the same physical size as "real world units" (so
that a logical centimetre on a printer is exactly the same size as a "real
world" centimeter as measured with a standard ruler. A 10 x 10 cm rectangle
when sent to a printer page will come out at exactly 10 x 10 "real"
centimetres when you measure the output with a standard ruler, and it will
most definitely be square as well! Obviously, things being what they are in
this world, there may be some very slight differences in the size, but it
will be a *very, very small percentage* difference and for all practical
purposes the size on the printed page will always alwayas be *exactly* what
you want it to be.

So, when talking about the monitor display this statement of yours about
"the viewable part should in my opinion be 14 x 9 cm" cannot possibly be
achieved! The best you can do is set the "logical" size to 14 x 9 "logical
centimetres" and hope that it comes out right. Of course (as you should
already know) it will almost *never* come out right! The actual displayed
size when measured with a standared ruler will be different on different
machines. This doesn't matter of course in practice. People almost never put
rulers up against the screen and measure the actual size of things! And even
if they do then they will almost certainly always be disappointed!

You can, of course, set the "logical width" to 14 centimetres and the
"logical height" to 9 centimetres and display it at that size. However, even
doing that is not what I would personally advise. This is because ion some
machines a "14 x 9 logical centimetre" rectangle will occupy almost all of
the display (and it will look quite large), and on other machines it will
occupy just a very small portion of the display (and it willo look very
small). My own advice would be to simply decide "how much of the available
screen real estate" you want your 14 x 9 cm rectangle to occupy, and to
arrange your VB code so that it displays the rectangle taking up
approximately that amount of "screen real estate" on all machines. This is
very easy to do, and it makes your "14 x 9 cm" card look right on all
monitors. Personally I would make your "fixed size" VB Form take up about
two thirds of the available screen space on all machines and I would reserve
about a third of the client area of the Form (or whatever) for your menus
and your horizontal scroill bar and stuff, making the picture of the "14 x
9" postcard fill the remainder.

The actual "full size" picture of the 14 x 9 postcard (your 1667 x 1078
pixel bitmap) would remain hidden in memory of course (in the Image property
of our Autoredraw VB picture box) and that is the image you would send to
your photoshop (the displayed image on the screen would simply be "thrown
away" when there is no longer any need to display it). The printing agency
could of course print your postcard at whatever final output size you
required (subject to "quality" limitations) and they would of course print
it at your specified 14 x 9 centimetre size. Printers of all sorts (old
fashioned impact dot matrix, modern inkjets, lasers, commercial printing
machines) are all *extremely good* at printing stuff to the page at exactly
the physical size you require. It is just monitors that are rubbish at this
sort of thing!

By the way, one other point is that images such as you are creating (which
contain mainly text and boxes and line graphics and other things with just
the odd bitmap picture or so) would be much better off being produced as a
metafile (.wmf) or other similar "vector drawing" file format, but
unfortunately VB does not provide any native functions for creating such
things and it would be just too much like hard work to write code to do so
using the API (at least for the job you are doing). Anyway, at the pixel
size of the image you are creating, a bitmap (or jpeg) will be just fine.

I'm sorry that I haven't actually been of any use to you in this reply (as
far as getting on with your code is concerned) but I really do feel it is
important to get this "size thing" out of the way before we start. Anyway,
have a think about this and let me know what you decide to do.

Mike



.

Relevant Pages

  • Re: Starting a Thread takes too long
    ... the normal thread pool, you can actually have more then one ... If one rectangle is finished, ... event in the UI thread to update the display. ... With shadows disabled, computation takes 2.5 s, with shadows enabled gives 60 s. ...
    (microsoft.public.dotnet.languages.vb)
  • newbie and DrawImage
    ... My application has a form which should display an image at an arbitrary zoom ... and optionally draw other images onto the ... // calculate the destination rectangle scaled according to _fScale ... creates display errors on the sides opposite to the direction of scrolling. ...
    (microsoft.public.dotnet.framework.windowsforms)
  • Re: Update value of VBA variable on a form in text box
    ... Public Function GetStartTimer() As Single ... Public Function ScreenUpdate() ... ' Each rectangle will turn Green in sequence ... 'For now I would like to be able to display the "Start" variable ...
    (microsoft.public.access.queries)
  • RE: Need help with D3DXMatrixOrthoLH
    ... > I am trying to draw a rectangle enclosing a rotating 3D object. ... > I am using D3DXMatrixOrthoLH to position the rectangle. ... Or the size of the display surface ... > g_D3DDevice.SetTransform D3DTS_WORLD, matIdentity ...
    (microsoft.public.vb.directx)
  • Re: No fill colors on screen, but prints ok
    ... I create a rectangle using the rectangle tool and ... >>View, pictures, click detail display... ... >>Mary Sauer MS MVP ...
    (microsoft.public.publisher)