Problem with transparency

[WilderBock]

I have been a big fan of PaintShop pro since the olden days. But hat I have always had a problem with is transparency. When I want to make a color transparent, PSP always wants to reduce the number of colors to 256. A problem that I don't know from other graphics programs like Gimp.
If I do something wrong, is it possible to work around the problem or is PSP actually limited in this point, and if so, why?
I am currently using Corel PSP XI for testing purposes.

[migf1]

Hi WilderBock,

I am not sure if the following options are available in XI, but they are since at least X7.

Try saving your PNGs via the exporter, with these settings:

PS. If you still have issues, try also these settings:

[migf1]

Just to add some info, there are 2 kinds of transparencies: single-color and alpha-channel. Single-color transparency (or palette-indexed transparency) in 256-color images is just one of those colors flagged as transparent. Alpha-transparency is what most people use (it is way more flexible).

[WilderBock]

Yes, exactly. Alpha channel transparency is what I meant.
So I can only set the alpha channel when saving or only work with alpha channel in PNG format?

[WilderBock]

Okay, now I know how to export an alpha-channel PNG. But it seems to me that I can't use an alpha channel while editing an image.

It's best if I describe what I would like to do.
I have a collection of pictures of vehicles with orange background. I want to make thumpnails from them, with a transparent background.I want to hide the background first, then reduce the images to the target size, and then I want to add a dark grey drop shadow effect to the vehicle on a transparent background. Alls this should happen with a batch script.

Unfortunately, when I resize, the contours of the car get mixed up with the background color, and the drop shadow effect is dark orange.

[JoeB]

I have a collection of pictures of vehicles with orange background. I want to make thumpnails from them, with a transparent background.I want to hide the background first, then reduce the images to the target size, and then I want to add a dark grey drop shadow effect to the vehicle on a transparent background. Alls this should happen with a batch script.

Unfortunately, when I resize, the contours of the car get mixed up with the background color, and the drop shadow effect is dark orange.

I'm not sure I understand your last sentence. If you have first removed the orange background from around the vehicle then that area around the vehicle should be showing transparency. So when you resize the image there shouldn't be a background color for the car to be mixed up with.

Perhaps the problem is that when removing the background orange color you have left a small amount of orange around the vehicle sort of like a border. It might even be semi-transparent and perhaps you just didn't notice it on your monitor.

[migf1]

Okay, now I know how to export an alpha-channel PNG. But it seems to me that I can't use an alpha channel while editing an image.

It's best if I describe what I would like to do.
I have a collection of pictures of vehicles with orange background. I want to make thumpnails from them, with a transparent background.I want to hide the background first, then reduce the images to the target size, and then I want to add a dark grey drop shadow effect to the vehicle on a transparent background. Alls this should happen with a batch script.

Unfortunately, when I resize, the contours of the car get mixed up with the background color, and the drop shadow effect is dark orange.

I think your cars are not saved with an alpha-channel in the 1st place.

Very few image-formats support transparency, PNG being among the most popular ones. If for example your car images are JPG images, then they do not have an alpha-channel (the JPG format does not support it), hence no transparency. Also, if they are in PNG format, but they contain no transparent areas, then again they will not include an alpha-channel.

Bring the car image into PSP, then in the layers-palette right-click on it and select Promote Background Layer.... this pretty much means "add an alpha-channel". From now on, when you remove the background, you should get transparency on the "empty" areas. When done, save/export it as PNG with alpha-channel transparency.

[WilderBock]

:Yeah, that's it! Very big thank you!

[migf1]

Yo are very welcome!