PaintShop Curves

A PaintShop Curves adjustment may well be one of the most useful and powerful adjustments in Paint Shop Pro.

Changing the curve can change the color, contrast and brightness of an image.

At first it may seem to be a bit of a fiddly adjustment but once you understand how it works it will become one of your favorite adjustments.

In some regards a Curves adjustment is similar to a Levels adjustment.  What separates Curves from Levels is the ability to make minute tonal adjustments that can be done over the entire tonal range of the image.  

This powerful adjustment can also be used to adjust color and tone in an image.

If you're looking for more creative things that can be done with PaintShop Curves then you're in luck - Terry has written two ...

Creative Curves

Image Toning


This is a long tutorial so to make it a bit easier to find what you want here are the on-page links to the different sections.



The PaintShop Curves Dialogue


This is the PaintShop curves dialogue.

Preview - shows or hides the two Preview windows.  

  • If you're using the eyedroppers then the Preview must be showing.
  • If Preview is not checked and an adjustment is made to the curves then the change will be visible in the right (After) Window and the original will be visible in the left (Before Window).
  • If the Preview is hidden the put a check mark in Preview on Image.

Settings - save adjustments or Revert to Default.

Auto - click on the Contrast, Color or Levels button to let PaintShop determine the best settings.  

  • Contrast moves the Black (bottom left) and white (top right) points to the edges of the Histogram in the centre window.
  • Color sets the Black and White points.  
  • Levels does exactly what the Contrast button does.
  • Options set the clipping limits for the Auto adjustments.  A higher setting will result in stronger Auto settings.

The Auto settings on the PaintShop Curves dialogue are OK but there's not much fun letting the program decide how an image should look, is there?  Give them a try.


Main Adjustment Window

This is where all the fun with PaintShop Curves lives!

Channel defaults to RGB and you can choose to adjust the Red and Green and Blue Channels individually. This is where you can do some creative stuff.

The Histogram for the image is visible in  the 4 X 4 sections.  The Curve is the straight line starting on the lower left (the shadow area) and ends on the top right (the highlight area).  When a point is placed on the line (left click or tap with your pen) then the Input and Output numbers will be the same.  When the curves is moved up or down the Input will stay the same and the Output will show the new number.

The Eyedroppers allow you to set the Black, White and Gray points in the Before window of the Preview section.

We'll look more closely at the various adjustments (Contrast and Color Correction) that can be done with PaintShop Curves.


PaintShop Curves
The Basic Adjustments

PaintShop Curves Acting Like Levels

At their most basic, Photoshop Curves are a lot like a Levels adjustment but with much more mid-tone control.

For instance, take this image as an example - it's rather flat (lacking contrast) and the Histogram does not fully extend from pure black to pure white.




By simply moving the Left end of the Curve (the black end) up to the base of the Histogram and moving the right end of the Curve (the white end) down to the where the histogram rises - just like this ...





This is where things end and it's a nice improvement - simple, right?


Modifying The Curve

Modifying PaintShop Curves is not much more difficult.  The most effective adjustment is to make the curve into a slight "S" shape by adding and then moving points on the curve.


Not a totally bad photograph but perhaps a bit of improvement in contrast would help.

Adjustment Steps

  1. Point 2 - this one was placed by clicking on the line at the exact middle of the graph (it will move as the other points are adjusted).
  2. Point 1 - the top right point was moved to the left so it is directly above the rise of the histogram - this will lighten the image somewhat.
  3. Point 3 - this one in the white area of the curve was moved up up (by dragging with the mouse or using the up arrow key).  The image will lighten a bit more.
  4. Point 4 - this point in the shadow end of the graph was moved down (by dragging with the mouse or using the down arrow key).  This will darken the image and the contrast improved.
  5. Point 2 (again) - dragging this point down darkened the mid tones - juuuust a bit.

And here is the result of these PaintShop Curves steps ...

Every image will, of course, need a different adjustment.  Play with the PaintShop Curves and remember to keep the adjustments small.


PaintShop Curves
The Droppers

The Droppers in the PaintShop Curves Dialogue are a quick way to correct the color in an image.  Having said that the Droppers would work much better if they could be used in the main image window.

As it is, they can only be used on the tiny little Before Window at the top of the PaintShop Curves dialogue.    With this limitation you can still use the Black and White Dropper to locate the corresponding points and that's what the following steps will demonstrate.

The Grey point is a bit more difficult to locate but it can be done - the limitation that Corel has created is the inability to use the Droppers on the main image.

If you really, really want to know how to find the middle grey point let me know via the Contact Form and I will get back to you.

There are three Droppers under the main adjustment window of the PaintShop Curves dialogue.  They are, from left to right, Black, Middle Grey and White.

To correct the color in an image, select one of the Droppers and click it on the corresponding color (black, white or middle gray) in the Before Window.  This is what the PaintShop help files suggest - "click what you know to be a black, gray, or white point".

The trick is finding the correct black, white or gray spot by simply looking at the image.

Here's an example ...

The Dropper technique worked quite well in this instance.  This is what I did ...

  1. I studied the main image closely in an attempt to determine the whitest part of the image. That little area on the front part of Max's shoulder seemed to be the correct area.  The blackest area seemed to be the bottom of his nose.
  2. The white Dropper was selected, moved the image around (using the hand tool in the After Window) until that part was visible in the Before Window and then clicked on the whitest area in the Before Window.  This eliminated most of the blue color cast.
  3. The Black Dropper was selected next and his nose was moved into the middle of the Before Window and clicked once again. This produced a much richer black in the picture. 


How To Find Black White Points

The following procedures may or may not be of any use to you whatsoever, however it's a neat procedure to add to your PaintShop Toolkit and you will finally get to use the Threshold Adjustment Layer!

Here's the picture for this step.  I found this poor, lonely bike chained to a bike lock a few days after a major snowstorm - it was needing some love!  It's definite blue cast that needs some fixing. 

Black Point

This is what to do - first - Duplicate the Background layer - just because.

  1. Add a Threshold Adjustment Layer and move the Threshold all the way to the left (to 0).
  2. Press the up arrow key until some black dots start to appear - these are the blackest pixels in the image.
  3. Drag a vertical Guide and a horizontal Guide over the black point and turn off the visibility of the Threshold layer (it will be used to find the white point).
  4. Zoom in to the point where the Guides meet and make a mental not of where it is on your image.




The layers palette with the Threshold layer on top of the stack.


This is the default Threshold setting.  To locate the blackest point, drag the slider all the way to the left.  To find the whitest point drag the slider all the way to the right,


After locating the first dark pixels, click OK and then guides were dragged out to make it easy to locate them.  Zoom in to make sure you know where the point is located.  With the bicycle the Threshold had to be moved up to 26 (the slider was moved up farther to make it easier to see).



It's difficult to see the guides - they cross at the bottom of the basket just to the right of the seat post.

White Point

The same steps apply with two exceptions ...

  1. Activate the Threshold Layer and move the Threshold slider all the way to the right.
  2. Press the down arrow key until some white dots start to appear - these are the whitest pixels in the image.
  3. Drag a vertical Guide and a horizontal Guide over the whitest point and turn off the visibility of the Threshold layer.
  4. Zoom in to the point where the Guides meet and make a mental not of where it is on your image.

With the black and the white points located you can eliminate any color cast using the Droppers.

To do that scroll the After window so that one of the points is visible.  Select the corresponding Dropper and click on the point and the change will be visible in the After window and in the main image screen (if Preview on Image is selected).

Now do it again with the other Dropper on the other point - and here's the before and after ... the blue cast has been completely eliminated.

Clicking on those two little points (black and white) made a nice change in the image, which is visible in the Histogram.


Video - Using The White, Black and Grey Droppers


Video - How to find the White, Black and Grey Points


Solarisation

Way back in my wet darkroom days, I spent countless hours trying to create a solarised print with some success. Solarisation (or solarization, if you prefer) at its basic is turning blacks into whites and whites into blacks.

The procedure in the darkroom was to put the exposed paper into the developer and about 3/4 of the way through the paper was exposed to light for a second or two.

It worked occasionally!



The great thing is that one can do a great job solarizing an image with PaintShop Curves and here's an example ...

Both black and white and color images can be solarised.  Terry has instruction for the color version here so I'm going to concentrate on working with black and white.

It's surprisingly easy.




I saw this poster in a mall and was struck by the sheer beauty of the watch.  It has the potential to be an outstanding black and white solarisation.

Note:  there is an automatic solarization technique built into PaintShop Pro.  Give it a try (it's not particularly impressive).

Here are the steps to follow ...



  1. The background wasn't needed so I created a new blank layer, double clicked on the Background layer to change it to a normal layer and moved the blank layer below the background.
  2. The light and dark blue areas were selected and deleted using the Delete key. This produced a nice black and white with no background.
  3. The second step was to turn the image into black and white (Image > Greyscale).

Create the Solarization

Now that everything is prepared wwe can get on with the solarisation with PaintShop Curves.

Add a Curves Adjustment layer and put a point in the middle of the curve and then take the point at the top right and drag it down to the bottom.  The image will turn ghastly ...

Now take that middle point and move it up to the top of the grid.

That looks much better, don't you think?  Now for the final step - adjusting the curve.  

This part will depend on the image you're using.  For the watch I chose to place two more point as you see them and then dragged them in an equal amount toward the center of the graph.

Watch the image in the main window as you are dragging - it seems to work better if the two point are balanced and equal distance from the centre point.

Mess around with the points until you are happy.

For this image there's really one more step needed because the watch isn't popping the way I want it to.

The next step is to add another PaintShop Curves level and follow one of the earlier procedures.  For this one I selected to "S" curve method to improve the contrast - and then - just because I can and because it works so well - the Blend Mode of this layer was changed to Overlay (which darkens the darks and lightens the lights).

That small little picture doesn't do the final picture any justice so here is a larger version.


I've just gotta say - the procedure using PaintShop Curves is much, much easier than the old darkroom method!

If you try this I'd love to see your results - contact me through the Contact Form ...!I'll add it to the page if you allow it.


PaintShop Curves
Restoration


To see where this section is going hover your mouse over the following image.  This is an old shot in need of some TLC and modifying the curves certainly makes a very big difference!  

The change in this picture is dramatic.

family

Step One
Change to Black and White

When you have an image like this you will obviously have to scan it into your computer.  When you are scanning make sure you scan it as an RGB image rather than black and white. 

I don't know how you feel about the sepia color cast but I really don't like it.  For some reason it seems to make it very difficult to clean up any problems in the image - like scratches and dirt marks and folds and stuff.

There are a few different ways to convert the image to black and white ...

  1. Adjust > Color > Channel Mixer.  Move each of the sliders, in turn, up to 100 and when you find one you like, click OK.  (after some fiddling around I ended up with Red 15%, Green `0% and Blue 75%).
  2. Adjust > Hue and Saturation > Hue and Saturation and turn the Saturation down to -100, click OK.
  3. Effects > Photo >Effects > Black and White Film ...  Click Suggest Settings and then OK.
  4. Image > Greyscale.

Whichever method you choose - the new image will be much easier to work with!

Step Two
Adjust The PaintShop Curve

Now for the fun part of the Paint Shop Curves technique - adjusting the contrast with a Curves Adjustment Layer.

Create a new Curves Adjustment Layer - and put some points on the line like this ... 

Some things you need to know about this dialogue: 

  • the line is always at a 45 degree angle when you open the dialogue.
  • everything below the line is the dark area.
  • everything above the line is the light area.
  • you can place points anywhere on the line and move them up or down.
  • the steeper the line the greater the contrast.
  • the shadow area of your image is about 1/3 of the way up the line from the bottom left.
  • the mid-tone area roughly starts where the shadow area is ends and goes another 1/3 of the way up the line.
  • the highlight area starts roughly where the mid-tones end and goes to the top right of the line.

I placed two points on the line at the first intersection in the shadow and highlight area and then ...

  1. moved the highlight area up about 1/2 of the square
  2. moved the shadow area down about 1/2 of the square

This increased the contrast, darkened the shadows and lightened the highlights - like this ... 

  And this is the result of this adjustment ... 

Don't you find it absolutely amazing that those small adjustments with PaintShop Curves made such a large difference in this image?  I know I do - I'm in awe of curves - and how the heck do they do that with zeros and ones???


Paint Shop Curves are great! 

Curves on a Selection

See the little boy (I think its a little boy) in the white outfit on the left side of the picture?  His clothes are almost blown out highlights ... so lets fix it ...

Make a selection around the area that needs fixing and then Copy (Ctrl-C).

Make a new layer and then Edit > Paste Into Selection.

Highlight the new layer and give it name so you can keep track of things and then - create a new Paint Shop Curves Adjustment Layer.  This layer will only affect the selected area.

Put a point on the line in the highlight area and drag that point down into the dark area but only a little bit.  You can actually use your down arrow key to move the point and it is generally more accurate than dragging the curve with your mouse.



You can see how very little of a change is needed to make a significant change in the image.

When you have a bit of texture click OK, deselect and zoom out for a better look.  Turn the Paint Shop curves layer off and on a couple of times to make sure you are satisfied with the results. 



After Fixing the Dress

Now - ain't that an amazing change from the original?

The PaintShop curves adjustments do an absolutely amazing job!

Now there are some other problems that need addressing in this image but that is a tutorial for another time.  The most obvious problem is that the left side of the image is much brighter than the right side.  There is also a stain and some nasty blotches that need mending.

Those items are the subject of another tutorial so let's end with that.

Find yourself an old image and give this a try - it is really rewarding to take an image like the original one in this tutorial and a lot of fun as well - and after all - having fun with your images is important isn't it? 


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