Pseudo-HDR

tomculver · Jan 13, 2012

I've been experimenting with tone mapping on old digital photos that were unusable because of their lack of contrast, etc. What do you think of this? Before you could hardly make out what was in the pic.

http://www.tomculverphotography.com...Streams/i-VdvQr3r/1/L/Gulf-Coast-Swanee-L.jpg

Rephargotohp · Jan 13, 2012

Tone -mapping actually gives an image Less Contrast, The image was probably overly contrasty before that's why you couldn't make out certain areas. Tone mapping done like this actually makes all tones mid-tones. That is why some of your whites have become gray and you have very little shadow area.

I think you could work on it and some of the things you want to fix are; the ghosting around the trees try highlight smooting or less strength), some graying of the whites and then you need to add back in some shadows (black level) and you may have something then.

Good luch, Kinda fun to play around with isn't it?

Bynx · Jan 13, 2012

Tone mapping will not give you less contrast. The amount of contrast you get is whatever you want by changing the sliders. HDR image prior to tone mapping will flatten the image a lot and move the highlights and shadows more to the mid tones as Rephargotoph says but when you apply the tone mapping then everything changes. If you want a flat mid tone image you can get that or else you can get a high contrasty image. Your choice. You've done a nice job on your photo. I wouldnt consider it a throw away.

Rephargotohp · Jan 13, 2012

Actually no, a HDR image has a high Contrast ratio that is what makes it an HDR. You are taking ratios as the Human Eye sees, 10,000 to 1 and compressing them via tone mapping to a Lower contrast ratio that is visable on devices 1,000:1, So tone mapping makes an image have less contrast. How sucessfully you tone map the image depends on making sure it has as full a constrast ratio that your medium is capable of. If you looked at a histogram of this image I am sure you would seea big spike in the midtone and very little on either end, indicating a very low contrast image

I'm sure you will disagree...that's fine

cgipson1 · Jan 13, 2012

shot is way overprocessed... please post the original also

Bynx · Jan 13, 2012

The idea of an HDR is to darken the highlights and lighten the shadows which makes the image less contrasty. The scene is contrasty prior to any HDR treatment. I dont follow your logic.

unpopular · Jan 13, 2012

As usual, Bynx is mixed up.

The point of tone mapping is to decrease a high dynamic range image into a lower dynamic range which can be displayed or printed, and do so in a way that is natural. In a sense, we're always tone mapping whenever we take a picture and apply a curve, whether or not that curve is the default one, a custom one, or a custom one on top of the default one.

Dynamic range is the degree of amplitude, from lowest to highest, which a given medium can record measurable detail. Contrast is the ratio between the highest and lowest recorded value. A high dynamic range image is not "more contrasty" per sey, as contrast is relative to the dynamic range itself - it can however record more contrasty scenes.

--

Anyway, I agree. The shot is way over processed and is in itself distracting.

mistermonday · Jan 13, 2012

Rephargotohp said:
Actually no, a HDR image has a high Contrast ratio that is what makes it an HDR. You are taking ratios as the Human Eye sees, 10,000 to 1 and compressing them via tone mapping to a Lower contrast ratio that is visable on devices 1,000:1, So tone mapping makes an image have less contrast. How sucessfully you tone map the image depends on making sure it has as full a constrast ratio that your medium is capable of. If you looked at a histogram of this image I am sure you would seea big spike in the midtone and very little on either end, indicating a very low contrast image

I'm sure you will disagree...that's fine

Well, sorry but I am going to respectfully disagree with you. Tonemapping does exactly what the term says - it maps tones from one space into another space. This does not necessarily mean a reduction in contrast and almost always results in a more contrasted image. Just about every tone mapping module has a control (often called Strength) and it's primary function is to apply tonal inversions - the darkening of the highlights and the brightening of the shadows. This can flatten your image into nothing but midtones. However that control also works in a negative direction and can induce the completely opposite effect.
Next a good HDR s/w will provide a control to adjust high dynamic contrast as well as low dynamic contrast. It almost always has a control to adjust microcontrast. And some HDR apps provide specialized controls for adjustment of contrast at different frequency bands.
While tone mapping usually maps a high dynamic range image into a lower range, it does necessarily reduce any aspects like brightness and contrast. In most cases the resulting tone mapped image will have a broader dynamic range in the destination space than the same image processed directly in that same space.
If you are in doubt, you can always do the math.
Regards, Murray

tomculver · Jan 13, 2012

Thanks for all the comments. Here is a link to the original.

http://db.tt/S8WUOEcM

Bynx · Jan 13, 2012

And as usual unpopular is being an a$$ again.

unpopular · Jan 13, 2012

but a technically accurate ass nonetheless.

cgipson1 · Jan 13, 2012

tomculver said:
I've been experimenting with tone mapping on old digital photos that were unusable because of their lack of contrast, etc. What do you think of this? Before you could hardly make out what was in the pic.

http://www.tomculverphotography.com...Streams/i-VdvQr3r/1/L/Gulf-Coast-Swanee-L.jpg

May I post an edit?