Pan & Zoom and image resolution

[Rawcoll]

Hi Canuck

I just tried the P&Z filter and the P&Z photo interface on the map file in both X4 and X5. For me there is the same deterioration in both cases.

So it doesn't appear to be a version difference then.

I tried David's VSP and, yes, it appears to work well, but I am inclined to think that this is because in the original image all of the text is readable, and so it remains readable in the zoomed image, giving the appearance of retaining quality. As Trevor noted above, with my image, because there is so much detail, that as VSP initially re-sizes it to the video frame size all of that detail is lost and cannot be recovered on zooming.

Perhaps Roxio editing operates on the original file rather than the down-sized one, which strikes me as the 'proper' way it should be done. After all, what is the point of rendering at the end if it isn't to apply the editing operations to the original files (be they video or still)?

Ian

[lata]

As an aside, I also use Roxio Creator 2012 (which is now a Corel product) and I tried the P&Z on the map image in that program and I got excellent results.

Canuck----Which image did you use Davids or Ians?

Ian If you crop your image to 2128 x 2904 you would be working with same sizes as Davids---its a (portrait shape) the pan and zoom is much improved, cannot say its as good as davids image.

I have tried most formats and non seem that much better, i will send a cropped jpeg via e-mail, i have sharpened the image using photoshop.

Sample of image cropped and sharpened.

http://www.4shared.com/photo/kbPqJU8n/M ... furl=d1url

[Rawcoll]

Thanks Trevor. I think it re-affirms what I said in my previous post about the size of detail in the original image. With an input image of only 2128 x 2904, when VSP re-sizes down to 1920 wide not a lot of the information is thrown out the text remains quite legible and the image appears to retain quality. With my image so much of the data is lost when VSP re-sizes that text becomes indecipherable, and when zoomed in is still indecipherable. i.e. rubbish in, rubbish out!

Ian

[Rawcoll]

It is interesting to note that if I re-size my original file in my photo editing application (I tried both 3840 x 2160 and 2880 x 1620) and apply the P&Z to those instead, the quality of the zoomed in image is improved to the extent that some of the text becomes readable, though obviously not as good as using the PiP approach!

Here's a screen shot with the smaller of the input images. Compare it with the one in my post of 1 Sept.

Ian

[david1939]

I've been doing some experimenting. I made a couple of 9600x5400 images by scanning at high resolution (1200 dpi). One is a map but not with such tiny detail as Ian's, the other a page of pretty small print (the index of the road atlas). P&Z on each of these gave readable results even zooming up to the limit of 10x (1000%). I've also got a jpg I downloaded off the web some time ago, an antique map of GB, 6152x7260. Zooming in on that gives just the same results as Ian's. I've uploaded the files to 4shared, the VSP shows the various trials:

http://www.4shared.com/zip/jv6rcbQ1/new ... furl=d1url

I'm wondering if the issue is the degree of compression used in creating the jpg. In my own scans I used a "high quality" setting; my map is about 27 Mb. The antique map with much finer detail is only 9 Mb. Ian's Iceland with again finer detail than my own scans is 27 Mb. Zooming in on both the antique map and Ian's results in "blocky" appearance of the unreadable text which might be due faulty decoding of the jpg.

[Rawcoll]

Hi David

It is bizarre but you might have a point. I was about to say that I also have my map image as an uncompressed 150MB TIFF, and I still get the same result. But, it is actually a composite image of several photographs converted from RAW, but checking I see that I exported them from my RAW converter as jpegs, though I usually use max quality! Let me go back to the drawing board and see what happens if I use TIFFS.

Ian

Edit No I remember now, in the end I used a panorama making software to stitch the jpeg images together. Yet another variable!

[lata]

Hi

I agree with all your comments regarding compression rates. We shouldn't have to go to such extents to simply retain the original quality, I guess the software is at fault there.
We know that VS must be stripping the pixels but which ones does it choose.
If we used an image in size increments of the frame size for pal 576 as the height, then doubling this would give 1152, and again2304, 4608 and so on.
Using 5400 as Ians image
Maybe getting a bit picky........

David I will download your samples, thanks for that but you say the results are the same as Ians map..

I was intending to make several images at different pixel sizes containing text, then use Pan & Zoom on each.

[Rawcoll]

Just spent a while composing a response to David and it seems to have got lost in the ether!

So, to repeat, I carried out some further testing. In addition to creating the large jpeg I also created a tiff of ~ 150meg, and that gave the same results. But, I then remembered that I had originally created the image from a series of photos that I exported from my RAW converter as jpegs, and combined using panorama making software! Mind you, I always use max quality for the jpegs. So, I have done a series of further tests.

1. I exported the images from the RAW converter as tiffs with no compression and then combined them in the panao maker and saved as a tiff. I then used my photo editing software to overlay it onto a blue background to give the final tiff image of 9600x5400. The result of a x6 zoom is shown here:

2. I exported the images from the RAW converter as tiffs with no compression and then composited them in my image editor and overlaid them onto a blue background to give the final tiff image of 9600x5400. The result of a x6 zooms is shown here:

3. I resized each of the final tiffs to 1920 x 1080 and repeated the zoom test. As I can only upload 3 images I'll use the resized pano stitched one. The result for the composited one is much the same.

In conclusion it seems that using uncompressed files hasn't substantially altered the situation, certainly not to the extent that David's tests might indicate. Also, re-sizing the files using an external editor gives improved legibility over allowing VSP to do the re-sizing.

It still all seems rather bizarre.

Ian

[Rawcoll]

Oh and just to head off a question, the image size that I overlaid onto the blue background was 6485 x 4525, so not much smaller in height than the final 9600 x 5400 image.

[Howarda401]

If all you want is to zoom in on a high res picture. Couldn't you just use a photo editing program such as Microsoft paint to create a good quality zoomed image then input that into Videostudio. It would eliminate a lot of problems.

[lata]

Hi Howard

Thanks for the post, I think we are trying to find the reason why Video Studio looses so much detail when using P&Z on the large image. Or rather we know why, just don't know how to fix it without using another image.
Maybe we are expecting to much from the video editor?

We have cropped the 9600px image into 1920 x 1080 sections using an image editor and indeed the quality is retained, little or no zoom being require by VS.
Using 1920 x 1080 is of course HD video frame size so the image is quite suitable for 16:9 video.
I think Ian will use the original map as the background then apply some form of transition to the 1920 image, Picture - in - Picture seems to work quite well but am sure there are other options.

[david1939]

Hi Trevor:

I would be interested in seeing how PiP can produce the desired effect. I note that you sent Ian a VSP. Could you let me have a copy also?

Thanks!

David

[lata]

Hi David

Apologies, I had thought I had made this link available on an earlier post

http://www.4shared.com/zip/lsujgBVw/map ... furl=d1url

[david1939]

Thanks Trevor:

Is it an X5 VSP? When I try to open it with my X4, nothing happens!

David

upps sorry will send VS 4 version?

[lata]

Hi David

Are you able to download this zip file? contains VSP for X4.
Replaces the X5 VSP.
You may have to re-link to the images you downloaded earlier.

map P in P X4.zip

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