Is this a program glitch?

[MarkyW]

Wanted to see if this might be a glitch in the program and if anyone else can duplicate it. I'm using PSP 2020 Ultimate. If it is a glitch, should I start a support ticket on it

I haven't tried it on other blend modes. I came across this when I was trying to colorize a black & white photo and it does this in both the "Color" and the "Color Legacy" blend modes.

What happens is if the photo has the pixel/color depth set to be RGB-8 bit/channel, then you can adjust the layer opacity slider and see a difference, as you should. But if the photo has the pixel/color depth set to be RGB-16 bit/channel, then changing the opacity slider makes no difference.

Here the first photo shows an 8 bit photo with an area colorized red and layer opacity at 100 percent.

Here is the 8 bit photo with the layer opacity at 40 percent. You can see the difference in the colorized red area.

Here is the photo at 16 bit with the layer opacity at 100 percent.

And here is the 16 bit photo with the layer opacity at only 1 percent. No difference in how the colorized red looks. That can't be right, can it?

[Jean-Luc]

I confirm.
I also tested on my versions (X7, X9 and 2019). They all have the same behaviour in 16bit.

Why do you switch to 16bit? There is no difference if you come from a 8bit black and white image and change it in 16bit.

[MarkyW]

Why do you switch to 16bit? There is no difference if you come from a 8bit black and white image and change it in 16bit.

I scan black and white images in color and they are saved as 8 bit RGB, and so I have never noticed this behavior before because the opacity works the way it should in 8 bit.

When I found the tutorial for colorizing a black and white photo that is on the Corel Discovery Center page, it says to change it to 16 bit RGB. So I did what they said to do and that's when I noticed this behavior.

This is what they say: "The first step with black and white images is to made sure that the color depth is at least RGB 16-bits. This can be done by going to Image > Increase Color Depth > RBG 16-bits/channel. Whereas RGB 8-bit supports 256 colors, 16-bit supports 16.7 million."

I downloaded the image they use so you can work along with the tutorial, and their image is 8 bit "greyscale".

But I did read that camera RAW files are in 16 bit. And I do take my art photos in RAW format. I don't know if I would be using the Color blend mode on a color image, but it could be possible. But not with this glitch. The opacity won't work. I'll have to check if any other blend modes also make the opacity not work. I haven't come across this problem before with my art photos, but it could depend on what I'm doing to the photos.

[hartpaul]

The tutorial is here:
https://learn.corel.com/tutorials/color ... f7fc6-2ebe

and it and the video request converting to 16 bits.

The first step with black and white images is to made sure that the color depth is at least RGB 16-bits. This can be done by going to Image > Increase Color Depth > RBG 16-bits/channel. Whereas RGB 8-bit supports 256 colors, 16-bit supports 16.7 million.

then make the new transparent layer and paint and change blend mode and then try and change opacity and you get either 100% or 0% with nothing in between.

Now when I did this using PSP X3 or earlier as soon as I try and paint I get a warning

This does not occur with later versions and it appears that the image is required to be at 8 bits / channel giving 256 red x 256 green x 256 blue = 16.7 million colors. I suspect the confusion lays in referring to an 8 bit image where there is one channel going from black to white using 8 bits and 256 shades of grey. An 8 bit image is not the same as an 8 bits/ channel (sometimes referred to as a 24 bit image) .

[Jean-Luc]

When I found the tutorial for colorizing a black and white photo that is on the Corel Discovery Center page, it says to change it to 16 bit RGB.

IMHO, it is not necessary. When a black and white image is 8bit native, the different shades of grey are fixed to 256. If switched to 16 bit, no additional shades of grey are added. The image still contains 256 greys. And your PC screen is 8bit and your printer is 8bit: you will not see any difference.

But I did read that camera RAW files are in 16 bit. And I do take my art photos in RAW format. I don't know if I would be using the Color blend mode on a color image, but it could be possible. But not with this glitch. The opacity won't work. I'll have to check if any other blend modes also make the opacity not work.

If you are shooting in RAW in 16bit, your image contains more than 256 steps and it is better to continue to work in 16bit inside PSP, I agree. But a scanned greyscale image is not in 16bit.

About the layers blend modes, the two Color Blend modes (normal and Legacy) don't work in 16bit. The other blend modes are working in 16bit.