Highlighted

is this banding?

Community Beginner ,
Aug 16, 2020

Copy link to clipboard

Copied

Hi, I'm trying to figure out why when I save a .jpg of a solid color I get horizontal lines in the file but if I do the same color as a .png I get no lines. In photoshop itself there is no issue its only when I save does it occur.  I'm guessing its the compression not really sure but I don't understand why it would band on a solid color.

Topics

Import and export, Problem or error, Windows

Views

83

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more

is this banding?

Community Beginner ,
Aug 16, 2020

Copy link to clipboard

Copied

Hi, I'm trying to figure out why when I save a .jpg of a solid color I get horizontal lines in the file but if I do the same color as a .png I get no lines. In photoshop itself there is no issue its only when I save does it occur.  I'm guessing its the compression not really sure but I don't understand why it would band on a solid color.

Topics

Import and export, Problem or error, Windows

Views

84

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Most Valuable Participant ,
Aug 16, 2020

Copy link to clipboard

Copied

JPEG is designed for photos. Specifically photos, not other kinds of images. It doesn't work well for drawn graphics, solid colour etc. It wasn't made for that; artefacts are inevitable, and may sometimes be regular.

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Reply
Loading...
Adobe Community Professional ,
Aug 16, 2020

Copy link to clipboard

Copied

I don't see any banding or horizontal lines in either of those attached images (viewing on calibrated and profiled Eizo monitors).  Zooming in and checking pixels with teh eydropper reveals no lines - all pixels are the same.

 

Dave

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Reply
Loading...
Community Beginner ,
Aug 16, 2020

Copy link to clipboard

Copied

interesting when you open the jpg in photoshop there is no lines its when you preview the image and zoom in you see the lines

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Reply
Loading...
Most Valuable Participant ,
Aug 17, 2020

Copy link to clipboard

Copied

Because JPEG is lossy, different apps may get slightly different pixel values. Also, they may handle interpolation when you zoom in different ways. None of this is suprising. Just don't use JPEG for this kind of material, and now you have a solid reason not to.

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Reply
Loading...
Adobe Community Professional ,
Aug 17, 2020

Copy link to clipboard

Copied

It sounds like whatever app you are using to preview is not decompressing the jpeg correctly.

Dave

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Reply
Loading...
D_Fosse LATEST
Adobe Community Professional ,
Aug 17, 2020

Copy link to clipboard

Copied

This is a solid color area (sRGB 5-15-16), so no banding is possible. Banding is stairstepping between different RGB values.

 

8-bit data will always show 256 discrete values from 0-255. In addition, the jpeg compression algorithm can introduce color banding because the color component is much more compressed than the luminance component.

 

Beyond that, almost all the potential sources for banding are in the display system, and that's where banding usually happens. Whatever bit depth in the data, the display system always runs at 8-bit depth, unless you have an (expensive) 10-bit capable monitor and video card. All the potential sources for display banding are cumulative, stacking on top of each other, and the result can be highly irregular banding on screen.

Likes

Translate

Translate

Report

Report
Community Guidelines
Be kind and respectful, give credit to the original source of content, and search for duplicates before posting. Learn more
Reply
Loading...