Adjust Brightness/Contrast/Gamma/Balance for SELECTION ONLY

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btakacs
Posts: 15
Joined: Fri Mar 29, 2013 2:14 pm

Adjust Brightness/Contrast/Gamma/Balance for SELECTION ONLY

Post by btakacs »

Is there a way to adjust Brightness/Contrast/Gamma/Balance for SELECTION ONLY?

Image > Adjust > Brightness/Contrast/Gamma/Balance does that for the whole image.
Filters work for selection but I haven't found any suitable Filter.

Regards
Bence
cday
XnThusiast
Posts: 4396
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: Adjusti Brightness/Contrast/Gamma/Balance for SELECTION

Post by cday »

It works for me...

You need to check 'Apply to image' in the Image > Adjust window to preview the effect.

Edit:

When a selection has been made, the Before and After displays in the Image > Adjust window do misleadingly show the change as being applied to the whole image, but the operation is only in fact applied to the selection when OK is clicked.
btakacs
Posts: 15
Joined: Fri Mar 29, 2013 2:14 pm

Re: Adjusti Brightness/Contrast/Gamma/Balance for SELECTION

Post by btakacs »

For me it's not: it applies the changes to the whole image, not the selection only.

Additionally if I adjust Hue/Lightness/Saturation, then it additionally TURNS OFF the transparency of the PNG.

I use XnView 2.0.4 on Windows 7.
cday
XnThusiast
Posts: 4396
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: Adjusti Brightness/Contrast/Gamma/Balance for SELECTION

Post by cday »

I'm using XnView 2.04 on Windows 7 too and this is what I see:

Selection with the following settings:
Image_1.png
Image_1.png (23.66 KiB) Viewed 2635 times
Image_2.png
Image_2.png (15.69 KiB) Viewed 2635 times
And the result:
Image_4.png
Image_4.png (52.1 KiB) Viewed 2635 times
Edit:

You are making the selection before clicking on Image > Adjust > Brightness... ?
btakacs
Posts: 15
Joined: Fri Mar 29, 2013 2:14 pm

Re: Adjusti Brightness/Contrast/Gamma/Balance for SELECTION

Post by btakacs »

Ok, here is the result of my investigations:

This function works fine until I make the image paletted (Image > Convert to colours).
On paletted images that happens:
change_selection_on_paletted_image.jpg
change_selection_on_paletted_image.jpg (41.3 KiB) Viewed 2614 times
...and yes: I first made the selection and then did the adjustments.
btakacs
Posts: 15
Joined: Fri Mar 29, 2013 2:14 pm

Re: Adjusti Brightness/Contrast/Gamma/Balance for SELECTION

Post by btakacs »

So it is working this way:
- Converting the image to 32 bits (Image > 32 Bits)
- Adjust the selection
- Converting back to Palette (Image > Convert to Colours)
- Setting the transparent colour again (Image > Edit Palette > (Select colour)+ (Enable transparency) then (OK) )

Actually it was my fault: this is the issue of not knowing the underlying basic concepts.
Thanks to Batti for the Help
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