Mike Chaney's Tech Corner

Been away awhile  ;D

Wondering why SOME of my image thumnails and some of my soft proof images look really bad? Some, not all look very rough but print out just fine. By rough I mean crunchy, low resolution, looks like someone rubbed sand on them type of image.  ???

As is normal to Qimage, the thumbnails and the preview panel are low resolution.
Usually not that noticeable unless:

1) Image itself is low resolution.

2) The Thumbnail Quality setting is set to LOW! See Edit Preferences.

3) Too much sharpening applied to the image making that grainy sandy look.

Check it out and let us know.

Fred

This is what I mean. This image prints beautifully, smooth background, etc but in the previews it looks horrible.

(http://farm9.staticflickr.com/8145/7317346100_80055e302d_b.jpg)

(http://farm8.staticflickr.com/7233/7317346146_045b20f106_b.jpg)

Hi,
I think I've simulated your problem, see attached image below.
It's the same 400 iso long lens shot viewed in the QU comparator.
The image on the left has some Tone Targeted Sharpening (TTS) applied in the editor and has a similar "crunchy" looks as yours, ie. grain/noise.
The one on the right has some noise reduction (Shadow Noise ticked) applied in the editor which has smoothed out the grain.
I've not printed the image with the NR off but I have noted in the past that QU's wonderful printing algorithms do smooth out grain in a print.
I would say from that, your images are "noisy" and possibly over sharpened.  :o
Terry

I see that your screen snap is showing the Page Editor screen which shows a very low resolution image there too.
There's a button on the right side of that screen that currently says, Thumbnail and Small image.

Either click the HQ button or click that Thumbnail and Small box and change to All Images.

What do you see now?

Fred

I also see the name of the image: P1169196-Edit-Edit2.TIF
This suggests that you have worked this image over a lot, and perhaps in another application where too much sharpening was introduced???

Fred

The HQ button basically looks the same, crunchy  ;D

The image has been "worked over" but I wouldn't say its over worked at least from my perspective.

I typically run an input sharping which is very light, you really can't see it without zooming in +100 percent. I also do a targeted rather aggressive noise reduction on the background to reduce the noise or grain. I do this via the Pixel Genius Photoshop plug in where I paint in the noise reduction, avoiding the bird.  This image was not output sharpened except when printed in qimage.

Below is the image from my flickr account which was output sharpened for web viewing.  When viewed on my monitor in Lightroom/photoshop the image looks very good just like the qimage output. You cannot see the background grain on the monitor or print and the bird feathers are smooth but very detailed.

Just seems that the onscreen image in qimage really exaggerate noise/grain that does not show up in print. I thought softproofing would show as close as possible what the print will look like?   

(http://farm6.staticflickr.com/5250/5322419932_2677d91f53_z.jpg)

That leaves us with three options.
Either the image is grainy because the camera caused it, or you presharpened the image somewhere before QU, or you didn't de-bone the bird before you ate it, and it was "crunchy"

Iso 400 shouldn't be a problem with most cameras.
If the Hi resolution image is grainy, then the print should be grainy too.
That's what bothers me. It doesn't fit. Something is wrong with the information.

Fred

Yes ISO 400 is not noisy on this camera. I presharpen outside of Qimage, is that the issue?

Were the originals shot as Raw images?
Do you have the originals? If so, simply put that image into Qimage without pre-processing, and you will find the answer.

Fred

Thanks Fred but what i am reading suggests that unless I process my Ram image in Qimage there is a good chance that the preview won't look so hot. I am happy with the on screen images and the final output.

That's not what I am saying at all.
What I am trying to impart is this:
(First of all, I suggest a click on VIEW at the top of the Main screen, and then REBUILD thumbs. (Not refresh; REBUILD!)

Just in cast there was a problem with the thumb quality or even the monitor profile.
The reason Terry and I go back time and time again to using Qimage a problem solving tool is because it can be.
We do not know what you, or any other person does to his or her images before he/she tries to print them from Qimage. Then when there is a problem to solve, we can use Qimage as a starting point (even from the RAW image or a JPG from the camera) and know that we, Qimage, Fred or Terry will not spoil the image. We also get a level point from which to start to help.

Your complaint was that the thumbnails and the preview panel were "crunchy" or sandy looking.
You also said,
Since Qimage uses a low resolution image for thumbs and the previews (for speed), it becomes likely that you have a Thumbnail resolution problem, a thumbnail Quality setting problem or a lot over sharpened which looks worse in the low resolution samples.


Again the quote above tells us that you have a thumbnail problem.

Finally, we work our way down through the posts, and you say,
Now we have different data. The HQ button no longer uses the thumbnails.
You say the image looks "crunchy" even in HI Resolution.
So *that* says you over cooked something. The image itself is saved with too much noise or too much sharpening!


You had to have done it in Lightroom or some previous work station....
I have very little knowledge of Lightroom. I have no idea if you made layers and duplicated the unsharp mask layer (if that's possible) and when  you saved the TIF it added too much.
I have no clue.

I do know, however, what Qimage does with an image, and should you be kind enough to email one image to me (Original image), we could see what happened in an instant.
Qimage never alters the image. So whatever either of us does with the image, is easily tested and returned to original.

Remember, we only have your information that you give us from your posts.
That's why I ask for a test image. When the information from your posts has contradictions or doesn't point to a conclusion.
If the print looks good, no speckles, but the HQ button shows speckles, then I almost have to ask what printer and what paper?


Just trying to help!!


Fred

There's one other phenomenon that could be at play here.  It is possible that the tool you used to remove noise left a low frequency noise pattern when it was removed.  To see if this is the case, hover over that thumbnail with your mouse and press Ctrl-X on the keyboard to get a full screen view.  The first view that appears is the 1:1 view and you'll probably only see a portion of the image because it will be too big for the monitor.  Scroll around and look.  Does it look smooth at 1:1?  Then use your mouse scroll wheel or right click to zoom out so you can see the whole image on the screen.  Does noise magically appear as you zoom out, showing more/less noise depending on the zoom level?  If so, the noise removal tool left a low frequency noise pattern that, when viewed at a smaller size, becomes evident.  To solve that, try adjusting the filter parameters in your noise removal program.

Mike

Thanks for you input, and Terry's.  I looked at the full screen image and although you can see grain it is a really fine grain and in print and looks great.

1:1 screen shot.

(http://farm9.staticflickr.com/8145/7327971698_abcd8904ce_b.jpg)


On the next two images, if I used the scroll wheel back and forth I could get the image to display in "crunchy mode" and "normally" at the same image size on the screen.  I do this via cntl x for full screen, then scroll wheel to a smaller size then rock the wheel back and forth and sometimes the image will look crunchy and sometimes normal.

Crunchy
(http://farm9.staticflickr.com/8004/7327971858_ee56118dee_c.jpg)

Normal
(http://farm8.staticflickr.com/7223/7327971794_0045b27e9d_c.jpg)

The grain that you see in this image is more like what the grain looks like in print.
(http://farm6.staticflickr.com/5250/5322419932_2677d91f53_z.jpg)

Appreciate the input. Not trying to be confrontational so I hope you don't take it that way. I know the images may look over sharped in some of my screen shots which doesn't help my case much  ;D

Hope you don't mind me chipping in here... I had (or rather thought I had) a similar problem. I was working on an image recently which was done on a point and shoot, on the original image the colours were horrible and it was very noisy. But, it was a really beautiful photo worth printing in mono. I did a b and w conversion, tinted it but left the noise (I may have even added more, I don't remember) as it really worked well and added a nice sharpness. Anyway....
When I saved it as a Tif the thumb in Q was really grainy and when I then previewed it in q also, it was also really grainy too, looked the same at 100%. It had me scratching my head for a while as I tried resaving it and trying different formats to no avail. Then when I viewed it in PS it looked fine but when I zoomed it to 100% I realised that it was really that grainy after all!

So basically I think what is happening here is that Q seems to be less forgiving (but actually more realistic) when viewed at an odd zoom ratio.
Typically when you open up the preview window, depending on the size of the image, to get the whole image to fit onto the screen my image would have been at something weird like a 21% zoom so it's never going to render accurately. And likewise with PS, to get the whole image on screen it will end up being an odd zoom too (although slightly different because of the extra toolbars), it just seems that PS is more forgiving as it looks great when in reality (at 100%) it isn't so much. I'm guessing that Q's interpolation is different to PS or other programs at different zoom ratios? Is this right?

As for the thumbs looking grainy, I actually find this helpful as I can see at a glance the full size image is noisy.
The only weird thing is when I saved a version from the same tif file as a jpg it looked perfect so I guess with the compression it just ignors the noise as being irrelevant.

Hope that sounds right? It's how my logic figured it anyway.

Now I'll just go and switch on the other pc and and get some screen grabs to upload as my image is pretty extreme and worth a look.

Jamie

ps Mike already addressed the whole zoom ratio business, but I know from experience it's good to know other people are experiencing the same problems (or  rather what initially seem to be problems), all too easy to think that you're going mad.

So this is the thumb view, the jpg is saved from the grainy tif file at highest quality and the grain is ignored.

This is the PS preview, it's obviously at a weird zoom ratio so not accurate but it seems to gloss over the details more than Q.

And this is the Q preview, again at a weird zoom ratio. Again, won't be accurate but at least it hints at the details/noise.

And both at 100% (ignoring the different crops). The same as should be.

Q at 100%.

Also, have to just mention that when printed and viewed at a better ratio like 50% the noise is perfect and the image looks great!

Shouldn't I be able to press the softproof button and get something that is close to what the final output will look like or do I need to sharpen/de-noise my image to conform to some threshold?

My understanding is that photoshop and some other programs anti-alias the display. This tends to hide the noise in the image, I guess their thinking is that often images are downsized and then the  noise disappears. However when you manipulate the image, (sharpen, add contrast, etc.) the noise increases. Since it is the display that is anti-aliased, the file itself will not be affected (except by sharpening, etc.) and will print OK.

Best wishes,

Ray

The Soft proof gives you a look at *approximately* what your image looks like when the monitor profiled image is compared to the printer profiled image.
It's a quick preview of something.... not sure of its value.
The printer profile is designed to match the paper and the ink and adds or removes contrast, saturation, hue, etc. That affects the softproof.

Try it... you see that applying a different printer profile to the setup can change the soft proof view dramatically. See screen snaps.
Guess which one is the soft proof image. 

You would be so far ahead if you would either print a small test print on the paper you are going to make the final print, or if that presents a problem because you need to see sharpness of a certain wedding dress at the correct print size, you should use the test strip feature in Qimage Ultimate.
The last screen snap is a test strip image it is a crop of the original, *BUT*, the ppi  of the full size print is retained.
In other words, the sharpness and definition of the center of that flower is exactly the same as it is when you print your large print.

I hope that helps a little

Fred