High resolution picture on low resolution big monitor

[Felix_Silvetris]

Hi!
I have a dilemma with a high resolution picture that I want to use on a large screen. The problem is the screen has a low resolution which seem to distort the picture sometimes. Also I would like to zoom in the picture.

The monitor is a 47 inch HP LD4720tm sporting a 1,920 by 1,080 resolution. So the resoultion is like an ordinary desktop monitor but the size is more than double that. In other words, the pixel density (ppi) is much smaller.

The picture is of a clock. Size is about 670X670 pixels. I cropped out this clock from a larger 12MP Raw format Nikon picture. The cropped out clock looks something like this (my real image is copyright protected but this is very similar with 700x644px):


(http://www.stanleylondon.com/ClockShipsBellSml1.jpg )

On the screen this picture should take up a fixed size of 170X170 pixels (ie about 10% of the monitor).

The first way I did this was to simply in Photoshop Elements save the 670X670 picture as a png and with dimensions 170X170 pixels. ("Save for web" to get it as small in size as possible and chose png and 170X170). Then I put the 170X170 pic on the background canvas. It looks very nice. However, when I zoomed in the numbers and other details look very jagged or blurry.

So now I tried with the larger resolution 670X670px. I put this on the background too, and as it should only take up 170X170px, I clicked it and dragged to resize it. But this picture looks much worse than the 170X170 pic. I suppose the 170X170 pic perfectly fits the 170X170 space while the 670X670px is distorted. I mean, for the 170X170 pic there will be one pixel for each monitor point. When I do the exact same comparison on a 21 inch 1920X1080 monitor they look equally good, so it must be due to the low pixel density of the 48 inch monitor where the human eye can see each pixel.

However, now when I zoom in the details for the 670X670px were clearly visible.

I tried a few other resoultions like 360X360 and 270X270 (I resized the 670X670 pic to these sizes) and both png and jpeg. They also looked worse in normal view but of course in zoomed view they displayed more details than the 170X170 pic.

My dilemma now is how to get an image that will look good both when zoomed in and when in 100% zoom (normal view) on this large screen. Is there a way to do this. Eg like resizing to a resolution larger than 170X170 that will also look good in normal view.

Thanks.

 

[Tom Mann]

If I understand you, you have a screen on which a small portion of it is normally used to display the clock (ie, 170x170 px out of a 1920x1080 pixel total screen real estate).

However, on some occasions, you want to "zoom in on the clock". I interpret this as meaning that on these occasions, you want to make the clock fill up much more of the screen (eg, say, 1000x1000px), and look nice and sharp and full of detail.

If this isn't what you meant, let me know and just ignore the rest of this post.

However, if my interpretation of your question is correct, then I think you are essentially asking for some means to turn a tiny, thumbnail-sized 170170 px image into a 1000x1000 px image, and recover all the details that were lost when you initially down-rez'ed the high rez starting image down to 170x170. Unfortunately, this is an impossibility.

Instead, for maximum sharpness in both sizes, you have several choices. The simplest approach is to separately store both the 170x170 and 1000x1000 versions of the image, and have your software display whichever one is needed. Or ... if you need to suggest the process of zooming to the viewers, you can either store a bunch of intermediate sizes and go from one to the next, or your software can dynamically re-size the 1000x1000 image down to whatever size (and placement) is needed at a particular time. This is a common problem in web design -- just Google {dynamically resize images}.

The bottom line is that if I understand you correctly, this isn't really a Photoshop issue, but a problem that should be solved with the display software, whether it is a browser displaying HTML or some other/custom software that you are using.

Anyway, I hope I interpreted your question correctly.

Cheers,

Tom M

PS - BTW, the pixel pitch of your monitor is essentially irrelevant to the question you asked. Specifically, from the point of view of down-rez'ing an image to get to the needed size(s), my recommendation for which down-rez'ing algorithm to use would be exactly the same whether you were using a high or low pixel density monitor.

 

[Felix_Silvetris]

Thank you. See these two pictures that show the situation:





First I created two png pictures of the clock, 172X178px and 540X560px respectively, in Photoshop Elements. Then I pasted these two pictures into our display software as show in the first pic above. Finally I "resized" the right larger pic to the same space as the left one. Maybe "resize" is the wrong word, because the pixels are still 540X560px. The left picture is not "resized".

Now this final picture (background+two clocks) is shown on a 1920X1050px 47 inch screen. The right picture (540X560px) looks more blurred as described in my first post. But when I zoom in the screen all the details of the right pic shows and the left one is blurred (because it is only 172X178px).

Yes maybe this is not a Photoshop issue. I think if the 47 inch screen had better resolution, the right pic would look nice in normal view, but buying a new screen is not an option now. It looked good on the 21 inch screen. It might also be possible to solve it in our display software with dynamically resizing (I will research this area a little bit more). Best solution, I think would be to fix it in Photoshop, but perhaps it is impossible.

PS. The two jpeg's above doesn't show that there is a difference in image quality, it is only seen in the computer screen.

 

[Tom Mann]

Hi Felix -

Although I'm very interested to know exactly what you did (ie, as described in your two posts), to start with, I need to know exactly what your final goal is. So, could you give me a response to the question I posed in my earlier post:

"If I understand you, you have a screen on which a small portion of it is normally used to display the clock (ie, 170x170 px out of a 1920x1080 pixel total screen real estate).

However, on some occasions, you want to "zoom in on the clock". I interpret this as meaning that on these occasions, you want to make the clock fill up much more of the screen (eg, say, 1000x1000px), and look nice and sharp and full of detail..."

So, is my general interpretation of your eventual goal correct? Or, is it correct, except that my guess of 1000x1000 px should be more like 560x560 px? Might you want two clocks on the screen at one time like in your first picture? etc. etc.

Thanks,

Tom

 

[Felix_Silvetris]

"If I understand you, you have a screen on which a small portion of it is normally used to display the clock (ie, 170x170 px out of a 1920x1080 pixel total screen real estate)."

Yes. It's like the situation in the last pic above. Imagine this pic is the screen.

"However, on some occasions, you want to "zoom in on the clock". I interpret this as meaning that on these occasions, you want to make the clock fill up much more of the screen (eg, say, 1000x1000px), and look nice and sharp and full of detail..."

Yes. Because the user might want to see some details of the clock.

"Or, is it correct, except that my guess of 1000x1000 px should be more like 560x560 px"

It can be to any size desired. 100% view as in the second pic above, 200% zoom (so the clock will take up 340px of the screen), 588% so it will fill up 1000x1000px etc.

"Might you want two clocks on the screen at one time like in your first picture?"

Yes, I think so. If you zoom eg 200% in the left corner both clocks will be visible.


Also, I think display software we use is vector based (like Corel Draw or Inkscape) but Photoshop is raster based. In the first pic I put the two photoshopped pictures into our display software (like putting it into Inkscape although I've never used this program?) . Then I resized the right 540X560px pic to the same "size" as the left 172X178px pic. Since the software is vector based I think the pixels are not reduced by the resizing and when you zoom the right pic will show more details. However, the left pic was resized in photoshop so it has lost pixels. The dilemma is that the right pic now looks worse in 100% zoom than the left one.

 

[Tom Mann]

Hi Felix - Thank you very much for the detailed response. Your final goal seems to be pretty much exactly what I thought it was. In that case, it seems to me that my suggestion (in Post #2):

"...The simplest approach is to separately store both the 170x170 and 1000x1000 versions of the image, and have your software display whichever one is needed...."

should do what you want, especially considering that one can separately optimize the sharpness of as many different sizes as you might need by always generating each different size from the full resolution version of the clock and down-rez'ing it, rather than changing the resolution in two or more steps (...which, I suspect, may be what you are currently doing, and which would of course lead to an unnecessary softening of the 2nd generation image).

Does this sound reasonable, or maybe there some reason that I don't know about which prohibits you from storing separately optimized versions of the clock image.

Thoughts?

Tom

 

[Felix_Silvetris]

I'm not sure but I think it might be possible. We have two modes of operation. One where zoom is possible and one where it is not. If both the 170px and the 540px are stored, it could be possible to make the first pic visible in non zoom mode and the other in the zoom mode. Thanks alot! It will require some more work to store two pics but if that is acceptable this might be a good solution.

 

[Tom Mann]

Hi again, Felix - I'm glad my suggestion might be useful to you.

The obvious next step is to decide on exactly how you want to sharpen each down-rez'ed version of the image. There are dozens of ways to do this, including native methods in PS. I've tried to keep abreast of developments in the area of sharpening, and my current favorite is NIK's output sharpener, "Sharpener Pro 3". So you could see how well it works on an image of a clock, I started with a 2000x2000 px image of a very ornate clock so that there was a lot of detail to preserve. I then down rez'ed it to 170x170, and 550x550 px using PS's "bicubic" method, and then sharpened each using NIK's sharpener.

The original plus the two down-rez'ed results are appended below.

Note: the in-thread forum previews are highly compressed, so to compare the versions, always double click the previews of the larger files, and you will get to an exact copy of the files I uploaded. You can then download them and view them using whatever software you prefer.

HTH,

Tom M