thad christian wrote:Newbie to Resolve...
Weird thing happening today. Imported a photoshop logo into resolve and I am having some weird speckles around the edges of the alpha. Played around with the clip attributes and switched between the modes and nothing could make the white dots go away.
Im sure it something dumb I am doing....but no clue at this moment.
Attached a screenshot.
There is a proxy button turned on in the screenshot you posted. Not sure if its related to proxy use, but that would be a thing to check. Turn off proxy to see if it changes.
Another thing could be just related to color space problem.
Usually putting "Color Space Transform" node and turning on: Saturation Preserving: This option has a smooth luminance roll-off in the shadows and highlights, but does so without desaturating dark shadows and bright highlights, so this is an effective option for colorists who like to push color harder. However, because over-saturation in the highlights of the image can look unnatural, two parameters are exposed to provide some user-adjustable automated desaturation.
Most of the time that will do the trick. Also if you are doing fusion stuff and you are seeing this in color page, make sure there are no negative values in Fusion. Just use Brightness Contrast [BC] node and make sure that these options are turned on.
Clip Black/White
The Clip Black and Clip White checkboxes clip out-of-range color values that can appear in an image when processing in floating-point color depth. Out-of-range colors are below black (0.0) or above white (1.0). These checkboxes have no effect on images processed at 8-bit or 16-bit per channel, as such images cannot have out-of-range values.
Pre-Divide/Post-Multiply
Selecting the Pre-Divide/Post-Multiply checkbox causes the image pixel values to be divided
by the Alpha values before the color correction, and then re-multiplied by the Alpha value after
the correction.
This helps to prevent the creation of illegally additive images when color correcting images with premultiplied Alpha channels.
The reason why it may not be appearing in the render is because some codecs turn on Rec709 and other options automatically in the Delivery Page. Anyway, when I encounter those issues, especially as mentioned with complex grades with DCTLs or complex Fusion comps, that is what I do and it solves the issue most of the time. Its just illegal out of gamut stuff happening that goes beyond color space of the project, monitor and output codec so you have to tame them.
If that does not help, not sure, maybe make sure you have no wild color settings in the project or color conversion nodes, including sometimes faulty or not well optimized DCTLs.
Hope it helps.
Also if you are in Fusion there is a problem of alpha multiplication.
Straight vs. Premultiplied Alpha | 3D Graphics Overview
Stop Transparency (Alpha) Changing in DaVinci Resolve Fusion (Pre-Divide / Post-Multiply)
Transparency and Color - Alpha Multiplication in Resolve/Fusion
Understanding Premultiply, Unpremultiply and Alpha Divide ( Fusion 8 )
CD / The Horrors of the Alpha Channel
Wed Mar 27, 2024 5:07 pm
