Preview image too light in Convert or Extract Chan

[jso]

Hello:

I'm using PicWinPro 5 and have been converting images from color to BW, using both Extract Channel and Convert

For both transformations the resulting images are about 20% darker than the preview image. I haven't noticed this discrepancy in other transformations.

Is this a bug or is there a setting that might allow me to fix it?

Thanks

[jsachs]

Unless you are previewing at a zoom factor of 1:1 you may not be getting an accurate impression of the preview image due to antialiasing artifacts. Also beware of apparent changes in brightness due to different viewing angles if one window is in a corner of the screen and the other is in the middle. If neither of these fixes the problem, post again and I'll try to figure out what's going on.

[jso]

The difference between preview and completed transform is measureable with the readout tool. It's less than I had first thought it to be.

For instance, a shadow reading 96.1 on the preview reads 96.9 in the transformed image.

As I say, I haven't observed it in other transforms.

--s

[jsachs]

A difference of 0.8 is pretty much invisible to the naked eye. There are a number of reasons why the preview might not match the final image precisely such as not previewing at 1:1 or working with 16-bit B&W images - the readout tool on previews is also not as precise as on a normal image. As far as I know there is no reason that Convert and Extract Channel should be any different from any other transformations in this regard.