Another use for texture mask - reveal the wire mesh

[Charles2]

I shot a landscape from a bridge through what I thought was merely a chain link fence. No problem, the lens could see through one of the openings.

Processing in PWP, I could not make the image good. My typical curve manipulations, local contrast with a high-pass filter, soft light, and brightness changes with a mask did not help.

Then I made a texture mask, thinking to experiment with heightening contrast through it. I moved the white carat almost all the way to the left and hit Apply. Lo and behold, the red mask revealed a wire mesh over the entire image. I had missed it completely while at the site concentrating on the scene.

The image revealed an oddity as well as my goof. I used an Olympus E-P1. As usual I processed the raw ORF file. But then I loaded the camera JPG into PWP and applied the texture mask. The mesh did not show up.

[Charles2]

Returned to the scene. There is no mesh there.

Working with a shot of a completely different scene, I noticed a similar but not as pronounced mesh or grid overlay, again upon applying a texture mask with the white carat moved almost entirely to the left. This image also showed a similar pattern, although not as pronounced, when I played around with the saturation contrast mask procedure using an absolute difference from the Composite menu, discussed in another thread here.

These manipulations create the mesh or grid artifact, or they reveal something about the Olympus E-P1 camera's sensor, AA filter, or raw engine.

[den]

If the image you are masking is derived from a jpeg file, you may be looking at the compression artifacts plus normal noise... the Mask Tool-Texture can be that sensitive with the settings I believe you indicate.

Illustrated is an Apply-Add texture mask with the settings I believe you are using where the left half of the image is in tiff format and the right half is in its 100% quality jpeg format:

Image_Texture_Noise.jpg (45.9 KiB) Viewed 3749 times

[Charles2]

Curious. I got the opposite of your result: the Olympus raw ORF file loaded through the Raw Dialog showed the mesh when texture masked, while the camera JPG did not.

[den]

I checked again/confirmed... the tiff image area of the illustration is the PWP RAW conversion of a Canon CR2 file and the jpeg image area is the tiff image saved as a jpeg file at 100% quality using PWP5's newer jpeg libraries... ... but then I normally use the MaskTool-Texture feature to find edges so do not normally include 'noise'.... ie... move the black pointer right to the highest histogram peak right-side base and the white slider left to where the lowest histogram element is first visible... this seems to produce a good edge mask without including the noise and/or 'mesh'.

[den]

Since you are experiencing a 'mesh' with your RAW files processed in PWP's RAW Conversion... have you considered changing to an alternate 'Preferred Interpolation' in the Advanced Settings section of the "File\Raw Settings..."?

For me a 'mesh' becomes evident when using PWP Jpeg files where the PWP5 Jpegs have a more intensive 'mesh' then PWP4 Jpegs, but then that may help explain why the file sizes for PWP5 are larger than those of PWP4 given the same compression quality and sampling.