Lighten background so it looks white instead of grey?

cwoodard

I'm having trouble figuring out a way to lighten a background in Lightroom or Photoshop. I've just set up a basic home studio and took my first photos, but I still need one more light it looks like, to point at the background.

In the interim, is there a way to do some post processing to make the background look more white and less grey? I can lighten them up a bit, but then I end up blowing out parts of the subject as you can see in the following photos.

Here are some of the photos of my son that I'm trying to fix:

<img src="http://www.woodardblog.com/photos/507504245_apXkb-L.jpg"&gt;

<img src="http://www.woodardblog.com/photos/507504572_6BoCP-L.jpg"&gt;

<img src="http://www.woodardblog.com/photos/507503055_PMhKq-L.jpg"&gt;

<img src="http://www.woodardblog.com/photos/507503614_K2fkH-L.jpg"&gt;

<img src="http://www.woodardblog.com/photos/507503751_kYCLm-L-1.jpg"&gt;

<img src="http://www.woodardblog.com/photos/507503912_n5tCH-L.jpg"&gt;

cwoodard

Oops I just found the following post in the stickies up top:

http://www.dgrin.com/showthread.php?t=4963

Sorry! This looks like it might help me

cwoodard

Well I'm still having a little trouble. When I do the color range and the feathering, I am having trouble not getting any of the subject included in the selection so the same parts are still getting blown out. Going to keep fiddling with it, but if anyone has any suggestions, I'd appreciate it!

Anthony

Whilst not an answer to your question, I would leave things as they are. The background and the 'floor' look just right to me in terms of complimenting the subject.

Anthony.

jjbong

Try this one:

http://www.dgrin.com/showthread.php?t=116223

It's an excellent tutorial by pathfinder on selecting backgrounds.

Art Scott

could also just remove the background and replace with a white one............

Thunder Rabbit

Howdy.

Ms. Woodward, you have just waded into the deep and muddy waters of "the selection process." Some selections are easy. Like the one in the tutorial. The background being lightened doesn't share any colors with the subjects. So it's easy to select with it with the color range tool (or the magic wand tool).

Some selections are hard. Like your photos. The skintones and background are too similar. You are not going to be able to do what you want with an automatic selection tool. It's a good way to start, but you've seen the limitations. You will need to tune up your selection manually. It can be a very tedious process.

In Photoshop, I would use the magic wand tool (W). Your tool options will be at top left. Choose "Add to selection" (The little boxes, second choice from left). Set a low "Tolerance", maybe 10. Check "Anti-alias", "Contiguous", and "Sample all layers".

Copy the background layer (not the backgound of your image). Then, click anywhere on the background of your image. A selection will appear. Click on the background again, in a different spot. The selection will be made and added to the first one. Ad infinitum. Keep clicking and more of your background will be selected. Clicking close to the edge of your son will define the selection more precisely. Keep clicking until everything you want gone is selected. It's kinda fun, and won't take long. If some of your kid is selected, don't worry. We'll take care of that later.

Now, invert your selection (Crl+Shift+I). Instead of the background being selected, now your kid is selected.

Click the layer mask button at the bottom of the layers palette (To the right of "fx"). This will create a layer mask (Its icon will appear beside the image thumbnail in the layers palette.. You kid will be visible. The background will not.

At this point, our layer mask is not perfect. But it's easy to adjust. If you haven't used layer masks before, the next part seems a little weird at first, but it works great.

Click on the layer mask icon in the layers palette (not the image icon). Now, you can use all kinds of tools to modify the layer mask. But we'll keep it basic and just use the brush tool (B). You paint on the mask with black, white, and shades of gray. Painting with white shows more, painting with black hides more. Shades of gray give partial transparency. I'd suggest sticking with black and white for now.

Zoom in real close so you can see what your'e doing. (Using two views can be very helpful. One so you can see the whole image, one at high magnification that you are working on.)

If you need to see more of your kids arm, paint it in with white. It will reveal more of the original image. If you want to get rid of more background, paint it black. It won't turn black, it will just dissappear, allowing the layer below to show through. For this image, I would make a new layer under our "backgound copy" layer, and fill it with black. It will make your brush adjusments easier to see.

Once your'e satisfied with what your layer mask is revealing, you can fill the layer below it with white, and now you will have your white background. And you're done.

There are more ways to make a selection than you can shake a stick at, and more ways to modify a selection than you can shake two sticks at. But unless it is a simple case, like the tutorial, it just takes some time. I've given you a simplified work flow, and the possible variations are literally infinite. But this should give you a place to start.

cwoodard

Thank you all for the wonderful help. I'm going to try this all out!

Thunder Rabbit

Howdy, again.

Or, if you have Lightroom 2 (Lr1, you're out of luck):

Select the local adjustment brush. Select exposure and set it to +3. Paint the background with the brush. It will turn white. Paint till you're happy. You can readjust the exposure setting while you're working, or any time later. And you can add more adjustment masks. Each with its own parameters.

The local adjustment brush can apply exposure, brightness, contrast, saturation, clarity, and sharpness. Singly, or in any combination.

It took about a minute to make the following adjustments in Lr2. It needs a little more work, but you get the idea.




I left the shadows at the bottom, because it seemed right.

If you wanted, you could select a new brush, and darken the kids left arm a little.

But the best thing is, try and eliminate such issues by your choice of background and lighting.

cwoodard

I do have LR2, and tried the adjustment brush as you described several times but keep giving up after 15 minutes. Even with auto mask on, I can't seem to get a smooth transition at the point where skin meets background. How did you manage that in a minute? I'm going to go back and try again, lol.

I do intend to fix the issue, because I sure as heck don't want to be wasting so much time in post processing. But I wanted to save these photos and the ones I took today of a friend's baby. Hopefully will get what I need for my little studio soon.

Using the first technique I found and linked above, I've been able to do this with the photos I took today. I could have made them whiter, but didn't want to get too harsh.

ttbest

Son's Pics
I LOVE these pictures. I think they're great! What kind of background are you using? Muslin, paper?? It's really nice.

cwoodard wrote:

I'm having trouble figuring out a way to lighten a background in Lightroom or Photoshop. I've just set up a basic home studio and took my first photos, but I still need one more light it looks like, to point at the background.

In the interim, is there a way to do some post processing to make the background look more white and less grey? I can lighten them up a bit, but then I end up blowing out parts of the subject as you can see in the following photos.

Here are some of the photos of my son that I'm trying to fix:

cwoodard

Thank you! I'm using paper.

ttbest wrote:

I LOVE these pictures. I think they're great! What kind of background are you using? Muslin, paper?? It's really nice.

Thunder Rabbit

Howdy.

Hello, Ms. Woodard.

For the adjustment I made on the image, I started with a large feathered brush (size 20, feather 40), and worked the outer edges first. I then made my brush smaller and worked closer to the boy (you can resize your brush by scrolling your mouse, the feather resizes proportionately). I kept using a smaller brush as I got closer to the boy. When I got really close, I reduced the flow to 30% to do the final detailing.

I've had mixed results with the auto mask feature. It tends to produce halos. I tried it on your kid, and got halos. So I unchecked it, and tried again. No halos. That's the one I posted. I almost never use auto mask.

And don't be shy about making your image really big so you can see what you're doing when you get to the detailing. Also, increasing magnification gears down the relative tracking speed of your mouse, making your movements more precise.

By the way, you're doing great. And you're definitely on the right track by not overdoing it. These are some great shots of cute kids (aren't they all).

cwoodard

Thanks again!

Still plugging away.... I'm now experimenting with the Magic Wand in PS to select the background instead of the Select Color Range. It's working pretty well I think.

rutt

I did this with PS in just a few minutes:

1. Convert to LAB
2. Make a curves adjustment layer
3. Apply image of the B channel inverted to the layer mask
4. Alt-Click on the layer mask to view it instead of the image
5. Auto-Contrast
6. Curves on the layer mask itself. Steepen completely so that the baby is mostly completely black and the background is mostly completely white. (Maybe could use Threshold instead of curves?)
7. Use the brush to clean up his eyes, the diaper, the shadow (should be white). This is easy because either you there is no close border (eyes, diaper, etc.) or the border isn't critical (basket, shadow). It isn't critical because of the way the following steps work.
8. Gaussian blur the layer mask about 3px.
9. Steepen the L channel curve of the layer (not mask) until the background is white and the shadow looks natural. This might lighten the bottom of the basket if you are careless (as I was) in step 7. But this will work out since the background is now much lighter. Using curves though the blurred layer mask means that the precision of the layer mask is much less critical.
10. Done!

It's a lot of steps, but no painstaking selection, which is what always takes me forever. In fact, it took me longer to write this than to do the edit.

Thunder Rabbit

Howdy.

Hi, rutt.

I liked the look of your technique, but I wasn't smart enough to follow your instructions. Step 3 baffled me.

"3. Apply image of the B channel inverted to the layer mask."

I selected the B channel, but didn't know how to apply it to the layer mask. And what layer mask? Do you mean the curves adjustment layer we just created? Do I convert the B channel to a selection, invert the selection, and then apply the selection to the layer mask? And what the heck is the B channel anyway?

Sorry if I'm being dense.

Thanks for sharing.

rutt

Thunder Rabbit wrote:

Howdy.

Hi, rutt.

I liked the look of your technique, but I wasn't smart enough to follow your instructions. Step 3 baffled me.

"3. Apply image of the B channel inverted to the layer mask."

I selected the B channel, but didn't know how to apply it to the layer mask. And what layer mask? Do you mean the curves adjustment layer we just created? Do I convert the B channel to a selection, invert the selection, and then apply the selection to the layer mask? And what the heck is the B channel anyway?

Sorry if I'm being dense.

Thanks for sharing.

You'll have a B channel after you Imae->Mode->LAB.

There is an "Apply Image" menu item in the Image menu. Select the layer mask for the curves layer you just created. Then Image->Apply Image. You'll get a radio box. Select the B channel of the background layer and check Invert in the radio box. Then it's onto the next step.

You can find out more than you ever wanted to know (but maybe less than you will be able to use) about LAB here.

pathfinder

Nice techniques, John.

Working through your steps, I used a Levels command, rather than a Curve for increasing the contrast of the mask of the baby.

Just drag the right and left Levels sliders towards each other, and then paint the eyes and the diaper black with the paintbrush and you have your mask. GB it.

Then adjust your curve for the white background, and you are done.


Even faster for this simple image than a pass through LAB, is to begin with the initial image, roughly select the baby with the Quick Select tool. Then use the QS tool with the ALT or OPT key held down to remove things selected but not desired. Next, use the Select>Refine Edge command to blur the edge of the mask. (I used a Radius of 4, a contrast of ~ 30, a Feather or 2, and an Expand of +2.)

A quick glance at the mask, by pressing the red chain link option at the bottom of the dialogue box, displayed the mask of the baby, and it looked satisfactory - no need to paint the eyes or the diaper, as they were picked up in the initial Quick Select grab. Invert this selection with Image > Inverse. You now have the background selected, and not the baby. A quick APPLE-L ( Command -L for Windows ) brings up the Levels command, and just push the right arrow to the left until the background looked as white as desired. The baby was masked so it was not affected. If you want to keep the shadow darker, push the left arrow on the Levels command to the right. Eeassy Peasy!

This is the basic selection technique I begin with today.

Building masks from channels is a good skill ( and still needed for hair and things like that ), but frequently not necessary today with the advent of the Quick Select Tool for an image a simple as this. This image was edited in less than one minute

My result is here

rutt

Pretty cool, Jim. I haven't used the QS tool before. Looks like it might actually be an implementation of the Bayesian digital matting algorithm I learned about in the computational photography class I took a couple of years ago. Using the B channel to make the mask was faster for me, but that's because I know the technique so well it's almost automatic.

I do have one refinement, though. Even though the selection is nice, I'd rather have a layer mask so I could refine with the paintbrush. So Layers->Adjustment Layers->Curve and Select->Reselect to make the selection into a layer mask in a curves layer.

cwoodard

I love this forum - thanks everyone! I look forward to giving these techniques a whirl later tonight.

rutt

BTW, it looks like the left side of his face (viewer's right) was a little bit of a problem for QS. The ear and the background are pretty close in color...

pathfinder

rutt wrote:

Pretty cool, Jim. I haven't used the QS tool before. Looks like it might actually be an implementation of the Bayesian digital matting algorithm I learned about in the computational photography class I took a couple of years ago. Using the B channel to make the mask was faster for me, but that's because I know the technique so well it's almost automatic.

I do have one refinement, though. Even though the selection is nice, I'd rather have a layer mask so I could refine with the paintbrush. So Layers->Adjustment Layers->Curve and Select->Reselect to make the selection into a layer mask in a curves layer.

John,

I did not go into adjustment masks here, because that was a little more involved, and not needed to simply whiten this background.

I, frequently, do use use the QS tool with the Quick Mask mode, and then save the selection as an alpha channel.

Some masks need very sharp borders for certain areas, say along a tree branch, but also very soft borders in other areas if a tree branch is poking up out of fog.

So I can grab the sharp area of the branch with the Quick Select tool and hit OK, then hit the Q key and go into Quick Select Mode, which displays the previously marching ants, as a red mask. I can then paint on this mask with the paintbrush in Normal mode, with black as my foreground color, and with a large soft brush, can then paint a very very soft graduated mask edge onto my earlier sharply outlined selection which is displayed in the red "photolith" mask.

Hit the Q key again, and I drop out of Quick Mask mode, and again see my marching ants selection.

This can then be saved of course, via Selection > Save Selection as an alpha channel. Then I have this selection available again whenever I need it. Or I can modify as needed, by using a Curve on it to increase contrast ala the method you discussed just above.

I wrote about this in this thread with your image of the tree branch that you so graciously donated

cwoodard

I should have posted the original version before I attempted to fix the background. Everyone has been working on a version that I had tried to fix - parts of my son ended up blown out. Here's a version before my first attempts to fix it:

Link to the original: http://woodard.smugmug.com/gallery/7832981_ZDzQi/4/510210774_bzfMa#510210774_bzfMa

<img src="http://woodard.smugmug.com/photos/510210774_bzfMa-XL.jpg"&gt;

pathfinder

rutt wrote:

BTW, it looks like the left side of his face (viewer's right) was a little bit of a problem for QS. The ear and the background are pretty close in color...

C'mon here, 30 seconds on a 70 Kb image, that I attached back up.:D

I assure you, that you can edit at the pixel level with the Quick Select tool if you have the time and the image, John. One of the tricks is not to paint with the Quick Select tool, but to use a very small brush ( hit the left bracket key several times to make it smaller ) and then to just point and click with the brush rather than painting with it. If you get too much, hold down the option key, and click outside where you want the selection to be, again without painting, just pointing and clicking with a small brush. You will find that at an image size of 100 or 200% you can refine the edge at the pixel level.

The QS tool is a bit of an acquired taste. I did not like it the first time I used it. There is a bit of a learning curve, but the trick is to vary the brush size, and point and click in addition to painting with the brush.

The QS tool is not limited to RGB either, it will work on just single channel rather than a full composite image. I just find it will let me grab large areas quickly, with far more precision than a Magic Wand or a Magnetic Lasso.

I rarely use any other selection tools now - I find the QS tool competes rather well with all the other selection tools available. I use them all according to what they are each best at, but overall, the QS tool wins hands down for me!

pathfinder

The real solution to these images is to separate the baby farther from the white background ( is it white or gray? It really does not matter )

With the infant farther forward from the background, increase the lighting on the background until it is ~ 3 stops brighter than the exposure for the infant, and the background will blow out, and go to complete white (255,255,255) without any editing at all.

You will probably need a gobo or flag or two to keep the light from hitting the infant also. Two speedlites with small Honl snoots will probably work as well

rutt

Jim, don't get me wrong. I was very impressed.

pathfinder

Glad to see you kibitzing again!