Correcting colour casts / White balance in Corel Paintshop Pro

Well, it's been almost a month since my last post.
Since this topic is part of what inspired the creation of this blog, I wanted to really dig into it and find a better way of colour correcting my photos. I needed a way that made sense to me and could be applied to any image, not just certain images.

Ever since I bought my first digital camera I've been struggling with the concept of white balance. Now white balance is not rocket science, but getting the colour in a photograph correct can be quite frustrating at times.

White balance in itself is not difficult to understand or correct and I'm not going to go into detail about what it is and how it works. This topic is covered in depth on thousands of sites so my focus here will be about how to do it instead of explaining what it's about.

So, what do I find so difficult about white balance?

I've spent years searching for a tool that makes white balance easy and in the last couple of weeks of researching the topic for this post, I actually found one.

Lets first look at how every other site tells you how to colour correct your photos. It goes basically something like this. Open the curves tool, select the black colour picker, click on a dark area of your photo and then do the same to set the white point.

Sound familiar? It should, this technique is the one you will find in basically every book and website that tries to explain white balance.  The other technique that you will see often is to create a new layer, fill it with medium grey, change the blend mode to difference and then to add a threshold layer to find medium grey in your photo. Then you again use the colour picker in curves to set the grey point.

This is all very well and works ok, to a degree, but what happens when your image has no pure white or black areas to select from? What if your photo has no grey areas either? With a photo like this, the abovementioned techniques become completely useless and it's because of this, that I've found white balance difficult because no one seems to know how to colour correct a photograph with no white, black and grey areas.

These kinds of photos make up about 60% of my photography so colour correction has always been a real pain in the neck, until now.

Ok, but before I get to this new technique, I'm going to show you how to do the first technique I mentioned, in Paintshop Pro because it does have value and may be useful for some images.

Alright, so let's start.

Open the image you want to colour correct in Paintshop. Click on "Adjust" in the top menu bar and then click on "White Balance".

Ok so this wedding photo has a really bad red cast to it. I added it deliberately for the sake of this post and now I'll show you how to remove it.

The first thing to do is to make sure your preview is switched on. To do this, click on preview in the top left corner of the White Balance Dialog.

Also, click on "Advanced Options" because the basic option you will never use.

Right off the bat, you'll probably notice two Temperature and two Tint sliders. The top Temperature and Tint sliders are the photo's original settings and you set these if you already know what the values are. Otherwise, just set Temperature to 5000K and tint to zero. The bottom two sliders are what you are suppose to use to set the colour temperature and tint of your photograph.
These work the same as any other photo editor and you should probably have set them already during the RAW processing stage.
Above the four sliders is the "Smart Select" button. We'll start with this.
Click the "Smart Select" button and Paintshop will set a marker on the "Before" preview image. This will normally be a white point and you'll notice a change in colour in the "After" preview image.

In this case Paintshop didn't auto select the ideal area so I selected a white area on the wedding dress that gave me a better result. To do this, simply click on the spot you want to select and the marker will move to that point.

Right, you will notice that Paintshop has now also changed your "Temperature" and "Tint" slider values and you can now fine tune using the sliders to your hearts content.

This white balance tool works amazingly well but as you'll see, there's still a cast to the photo because of how I initially added the cast. Again, this was done deliberately so I could show you what happens when this tool fails to remove a cast.

The second step, since the cast is not gone yet, is to use the curves tool.

So click on "New Adjustment Layer" at the bottom of your layers palette and click on "Curves".

This tool should look familiar, you have a histogram that you can tweak by setting and adjusting points on the diagonal line running through it, also you have the three colour droppers you use to select white, black and grey points to automatically adjust the curve.

This is what I've done here. You select the black dropper, then click an area in the "Before" preview image that you want as pure black. Then do the same for white and grey points.

Once done, your colour balance should be close to correct and you can still finetune by changing the curve manually and for each colour channel.

I've stopped here because I've found an easier way. As you can see, this image now looks a lot better but it's not what I want. The red cast is gone but now it's too cool and I want it warmer. I can do that with the curves tool but there's a quicker way that replaces the entire process.

Colour balance is subjective. What looks good to one person, looks horrible to the next. Then, there's "correcting for skin tones". People correcting for magazines love this phrase but tell me, when last have you seen a published portrait with accurate or realistic skin tones? It doesn't exist. People say accurate but what they really mean is, "what looks nice".

Anyway, the point is, correct colour for a photograph is what the photographer say it is. There will always be people who love what you've done and those that don't. The following tool will not only colour correct your photograph, it also has the potential to help you develop your own unique style in colour grading your photos.

Correcting colour cast is important because it's rarely the type of cast that you want so your first course of action is to remove it.

Corel Paintshop Pro has an amazing tool called "Histogram". And no, I'm not referring to the histogram displayed in the top right corner, I'm referring to the one under your adjustment layers which allows you to manipulate the colour of your photo by changing the histogram directly.

It works similar to curves but Corel has added more functionality that makes this tool great for colour correcting images.

Click on "Edit" and then on "Revert". You want to remove all the changes we made so far, and start from scratch.

Now, with the photo reverted back to it's original form, we can begin.
Before I start, I look at the main histogram in the top right corner and make sure that "Use all layers" is selected. You find this setting to the right of the main histogram. I also uncheck "Hue", Saturation" and "Lightness" so that the histogram only displays the RGB channels , that's all I'm interested in for the moment.

Click on "New Adjustment Layer" at the bottom of your layers palette and then click on "Histogram".
The histogram tool's dialog will now appear. Although it also displays the histogram for the photo, I like to position this tool so I can see what happens on the main histogram behind it while I edit. This allows me to compare how the different RGB channels relate and I can see when the histogram is "balanced". Just remember to check "Preview on Image" in the top right corner of the Histogram Dialog window, otherwise your main histogram will not update in real time.

In the Histogram Dialog, make sure you select the "Adjustment" tab. For colour correcting we don't want to work with luminance so next to "Edit", select "Colors".
Next to "Colours" you can now select the different RGB channels to edit.

Here I'm starting with the Red channel.

You'll notice immediately from the displayed histogram of the red channel that there's something seriously wrong with it. On the left of the histogram you can see that there's no red channel information in the shadow areas of the photo. Also, the histogram is broken up on the left hand side.

To fix this we do the following:

To the right of the histogram is a slider for the midtones that you can use to compress or expand them. Here I want to expand the midtones, so I drag the slider down until the Red channel histogram fills the entire space from left to right.

Alright, now there's no missing red channel information in the shadow areas anymore but the histogram is still broken up in some places.
Below the histogram there are three arrows which represent the shadow (Low), midtone (Gamma) and highlight (High) areas of you photo.
Click on the middle arrow which represent midtones, and start dragging it to the left until the histogram looks nice and solid, with no areas breaking up. You will notice that this changes the "Gamma" value just below the arrow and for this image I've set it to 0.67.

You'll also notice that the colour cast is almost gone from your photo already.

Next to "Colors", select the green channel.
I'm not making any changes here as this histogram looks correct and balanced, with no missing information in any area. Nor does it show signs of over or underexposure.

Next is the Blue channel.
Here again, you can see that it needs some tweaking.
There's very little blue information in this image to I want to make the most of what I have to work with.

Here I want to compress the blue channel midtones so I drag the midtone slider up, to a value of 10.
Then I drag the "High" arrow, under the histogram, to the left which adds blue to the highlights of the photo. Here I've set the "High" value to 244.

And that's it. I'm happy with my photo's colour. The red cast is gone and I have the warmth that I wanted to keep in the colours.
All with one tool, easy and quick.

Here's the result.



Now, just to prove to you that this tool will easily colour correct any photo, I will show you how it works on a photo with no white, grey, or black areas.

Here I have a macro shot of a Poinsettia. I used off camera flash which produced way to much red and for the sake of this post I converted straight from RAW without doing any adjustments.

I'm again using the Histogram adjustment layer.
Notice, I position the Histogram dialog so I can see my main histogram just above the dialog. On the main histogram I can clearly see there's no Red information in the shadows so I drag the "Low" arrow to the right until the main histogram shows that red fills the entire range. A "Low" setting of 17.

This image has a lot of red in it and it's over saturated so now I use the midtones sliders to remove some of the red by dragging it up to a setting of 10.

Next, the green channel.

Here I set the "High" slider to 225 and the "Gamma" to 1.06.
This boosts the greens and yellows in this image and makes them pop.

Next is the blue channel.

Here again I want to boost blue in the highlights so I set the "High" value to 223 and drag the midtones slider down to -9.

That's it. Colour corrected without white, grey or black points. This image still needs a bit of work in terms of contrast and boosting individual colours but that's done with other tools. The colours are now corrected and the red cast is gone.

What I like about this is that I don't need to figure out what tint to add or how much cooler I need to make it to remove the cast. With the other tools I spent hours trying to get the image on screen to look like the flower in my living room, without success.
With the Histogram tool I got it perfect in minutes. Especially the specific shade of red in this flower, which  I previously found impossible to reproduce without messing up the yellows and greens.

Below are the before and after images.

First is the original histogram.

 Second is the corrected histogram.

Notice that the corrected histogram looks much more balanced, with enough colour information in all areas.

Here are the results:



I hope this post has been helpful. Now you too can easily colour correct images where the traditional tools fail or make it a difficult and tedious effort.

Happy editing.


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