1

Topic: Photo Iso Print

I tried lenticulars years ago without much satisfaction.
One of the reasons was the printer output.
Wouldn't it be better to use photographic prints instead ?
Do I have to print to a file first or is there already a PNG (or JPG) output?

2

Re: Photo Iso Print

I'm not sure what you mean by photographic prints...
A good inkjet photoprinter has sufficient resulution to make good prints for the lenticular screens, but you can also export the image to PNG if you want to have it printed some other way.

Michael Vinther

> software developer <

3

Re: Photo Iso Print

More specific: if I create a 1919x1157 output png file and reduced its size to 810x 490 before putting it on a 1500x1000 jpg file which I then have printed in a photolab as a 15x10 cm photo  (that is, the result is photograph, not a inktprint) is that correct, or am I missing something ?

4

Re: Photo Iso Print

I have to say that i still don't understand... How do you create the output PNG? Why would you reduce the size to 810x 490 before printing it?

Michael Vinther

> software developer <

5

Re: Photo Iso Print

admin,Feb 1 2006, 09:52 PM wrote:

I have to say that i still don't understand... How do you create the output PNG? Why would you reduce the size to 810x 490 before printing it?

Must be my english ...

I ordered some minipopms lenticular viewers. They are really nice.
Some example interlaced image photographs  come with the delivered viewers. These photographs are about  79,5 x 48,5 mm big.

To make my own photographs I use your fine interlacing program.
Besides (inkt)prints it also creates a fixed sized interlaced image file.
This 1919x1157 pixel image file is created using the  File > Save > Interlaced image menu. I choose the PNG output format for quality reasons.

Next I have to prepare my JPG file that I will send to a online photolab ( like Fujilab or Kodak...). I use their standard 15x10 cm sized photos.
So,I create a JPG file of size 1500x1000 : evey cm now corresponds with 100 pixels. It means that if I reduce the size of the 1919x1157 pixel interlaced image to 795x485 pixels and put that in the 1500x1000 jpg file the resulting photo will show a 79,5 x 48,5 mm interlaced image, isn't it ?

Well, that is what I thought, but unfortunately the result is not working:
there is no 3d or animation at all.
Therefore I guess that the measured size 79,5 x 48,5 is not correct.
I understand that this size is crucial because it makes the photo fit with the viewer.  I also tried the 81x49 that appears when you prepare a print but this is too big for the viewer and also gives no result when viewed.
Therefore my question:

What size does the 1919x1157 interlaced image file have to have (in millimeters) before it can be used with the mimipopims viewer ?
Or am I doing something wrong here?

6

Re: Photo Iso Print

admin,Feb 1 2006, 09:52 PM wrote:

... How do you create the output PNG? ?

I created the PNG starting from two images (a stereopair).
Using the very effective Companion I combined them to build a stereogram.

The exact procedure goes like this:
1. Load program, select 'Minipopims landscape 30 images.
2. F3: load first image , F3 load second image, return to first frame(icon),
    open next primay frame(icon),  F6: tile the windows
3. Now i add some morphing points. I stop with the second window active.
4. I create a morf from the previous to the active frame (icon):
    It opens a window asking for confirmation and at the same time proposes       to reduce the framesize to 282x173.
    I accept (the program knows best) although I don't understand the meaning of this small size. I also accept next window that proposes 28 intermediate frames and smooth ends.
5. Next I open the animation player (icon) and am pleased with result.
6. Finally I create an interlaced image file in PNG format using the File>Save>Interlaced image menu which I then try to have turned into a photo as described in my previoous entry.

All in all, a very easy procedure thanks to the very clever program.
If only the result was of the same class...    sad

7

Re: Photo Iso Print

Hi Frans. Your English is fine - you were just not being very specific...  B)

It does not work for several reasons:
· The size is probably not correct. It should be 81.2 X 41.9.
· You cannot reduce the size of the image as you said you did - the resolution of the printer should be at least 600 DPI.
· JPEG compression may distort the small details in the image. You should use PNG or TIFF.

Michael Vinther

> software developer <

8

Re: Photo Iso Print

admin,Feb 2 2006, 11:38 AM wrote:

Hi Frans. Your English is fine - you were just not being very specific...  B)

Thanks Michael for the fast reply.

"It does not work for several reasons:
· The size is probably not correct. It should be 81.2 X 41.9".

This is very promising, I will try this out.
My only doubt is the correctness of the proportion: 81.2/41.9= 1,938 while the minipopims are 79,5/48,5= 1,64.
(you dont mean 81,2x49,1 by accident ?)

"· You cannot reduce the size of the image as you said you did - the resolution of the printer should be at least 600 DPI."
Well, I don't intend to print at all.
I only want photographs generated from  JPG files.

"· JPEG compression may distort the small details in the image. You should use PNG or TIFF".
When I reduce the 1919x1157 to  812x419 and next resize this again to 1919x1157 the compression artifacts almost invisible, so no harm here.
( I use 85% quality without colorsubsampling ).
Besides, most photolabs only accept JPGs.

Thanks for your information.
I would be happy if you could confirm that I have to reduce the 1919x1157 to
812x419 and not 812x 491 as I assumed.

9

Re: Photo Iso Print

Frans,Feb 2 2006, 01:51 PM wrote:

Ref my previous:
'My only doubt is the correctness of the proportion: 81.2/41.9= 1,938 while the minipopims are 79,5/48,5= 1,64.
(you dont mean 81,2x49,1 by accident ?)'

In fact, respecting the proportion of the output file:
1919/1157= 1,658599
and assuming that the 81,2 mm is correct
then 81,2/1,658599 gives 482 wich would fit into the minipopim ...
Am I getting nearer ?

10

Re: Photo Iso Print

Ref prev:
'...assuming that the 81,2 mm is correct
then 81,2/1,658599 gives 482'

in fact it doesn't  :blink:  it gives 48,957   sad

And assuming that 49,1 is correct
then the length is 49,1x1,658599=81,44.


Thus,
assuming proportion 1919/1157 is correct then
neighter 81,2x41,9
nor 81,2x49,1
fit the bill...  and

assuming 81,2x41,9 is correct then
its proportion (1,9379) is different from the one
used for the interlaced image file generated by the program
and it leaves a substantial part of the minipopim, which is about 49, unused.
So,...

11

Re: Photo Iso Print

The size I gave you is probably incorrect... I can see that Popims Animator aims at printing in 83x51.

Well, I don't intend to print at all.

Actually I think you do - the photolabs also use some kind of printer. I don't know much about this, but it could be a dye-sublimation printer. If 810 pixels gives you 81mm then it is only 810/81·25.4 = 254 DPI.

the compression artifacts almost invisible

A deformation that is almost invisible to you might still be very significant when viewed through the popims screen. Also note that the compression quality set for JPEG is not in %, so even if you set it to 100 the will still be a quality loss.

Michael Vinther

> software developer <

12

Re: Photo Iso Print

Thanks again for your answer Michael.

... the photolabs also use some kind of printer. I don't know much about this, but it could be a dye-sublimation printer.

My local photolab uses normal Fuji photographic paper and a RGB laser, no ink involved at all. But you may be right for other labs.

If 810 pixels gives you 81mm then it is only 810/81·25.4 = 254 DPI.

Aha, yes, I was expecting this. But when I compared my first results with the examples I got together with the minipopims, I found no visible difference using a 5x loup that's why I stuck to the 1500x1000 pixel jpg size with my second attempt. But I will try it with my next set.

A deformation that is almost invisible to you might still be very significant when viewed through the popims screen

Well, if that is so, than I am in real trouble because the online labs only accept JPG. Using PNG ot Tiff means that I have to switch to professional printing with input via CD or DVD and prices that are 3 to 10 higher and waiting times of days instead of hours.

admin,Feb 2 2006, 06:36 PM wrote:

The size I gave you is probably incorrect... I can see that Popims Animator aims at printing in 83x51.

Well, this is painfull because this is the first thing to get right I think.
DPI and compression artifacts may make it less perfect but an incorrect size makes it totally worthless as I saw with my own eyes I am sorry to say.
Well, 10 minipopims waisted is not the worst thing in life after all  wink

13

Re: Photo Iso Print

but an incorrect size makes it totally worthless

You are absolutely right, the size must match exactly for it to work. The interlaced image saved by Popims Animator for the Minipopims screen are ment for a pixel size corresponding to 600 DPI.

Michael Vinther

> software developer <

14

Re: Photo Iso Print

Thanks Michael

The interlaced image saved by Popims Animator for the Minipopims screen are ment for a pixel size corresponding to 600 DPI.

This is the answer I was looking for:
600 dpi means 600/254= 24 dots per mm (more exactly 23,6220)
wich makes the size of the 1919x1157 pixel interlaced image
equal to 79,9x48,2 mm (more exactly 81,2377x48,9797 mm).
Maybe you remember which value to use ?

If I now generate a file of 150x100 mm that is 3600x2400 pixel at 600 DPI
(more exactly 3543x2362) and copy the interlaced file in it I should get what I want, assuming that the photolab respects the 600 dpi. Sounds promising!

I just sent in some pictures to test this new findings.
I will inform you about the results. Thanks again ! wink

15

Re: Photo Iso Print

To conclude a long story:

it was my intention to use photographs instead of (ink)prints for reason of quality and price.

The photoprint labo's I contacted all print at 300 or 400 DPI.

PopimsAnimator outputs 30 images at 600 DPI which means (I think) that there are 20 lenses per inch (LPI).
Using these lenses at 300 iso 600 DPI means that only 15 images are possible.
Since the size of the popimg print should remain the same it means also that the size in pixels has to be cut in half (  960x579 iso 1919x1157 ).
Standard photoprints are 4 inch x 6 inch meaning that at 300dpi the popimg has to be put in a 1200x1800 pixel image.

To verify this I prepared a stereopair: I used 2 input images (no morphing involved)
and saved the interlaced image (1919x1157 pixels).
Then I made two reduced-size versions: one 960x579 pixel and the other 959x578
and put them on a 1200x1800 pixel image.

I sent them to 3 online photolabs that garanteed me to print at 300 dpi full size.
One of them is a professional site : they asked me to send the original 1919x1157 version and they garanteed that its photoprint would have exactly the size of the 600 dpi version.

Well, to cut this long story short: it did not work.
There is a lot of ghosting (one eye seeing part of the image destined for the other eye).
I also tried using morphing-animations with 15 frames: even worse.
My last hope was that there is a small variation in the quality of the lenses: I have ten of them and they all give the same result.

So, dear administrator, since this topic leads to nothing good, I have to ask you to remove all these 'Photo iso Print' entries from the forum.
If I ever find a solution I will tell you.
This will not be very soon however because I am a bit fed up with it right now.
Thanks.

16

Re: Photo Iso Print

I can think of one thing that could be the epxplanation: Are you sure that their printer is 300 DPI and not e.g. 300.1 DPI? Also with normal inkjet printers it may be necessary to adjust the images if the resolution is not exactly as specified. Did you that the print dialog has an option called Printer adjustment which will allow this? There is some more explanation here.

By the way - I will keep this thread in the forum, if nothing else then as a warning to others who might try something similar smile

Michael Vinther

> software developer <