# Libpng errors

## Problem

Some changes in libpng version 1.6+ cause it to issue a warning or even not work correctly with the original HP/MS sRGB profile, leading to the following stderr:

    libpng warning: iCCP: known incorrect sRGB profile

The old profile uses a D50 whitepoint, where D65 is standard. This profile is not uncommon, being used by Adobe Photoshop, although it was not embedded into images by default.

## Solution

The simplest solution is simply to remove the embedded profile from your image. This can cause a slight shift in color *IF* you have a properly calibrated system, monitor, and software. If you really need it (say for a print shop), you can alternatively embed a different color profile. If this applies to you, you probably have the profiles you need already.

### GIMP

To remove the embedded profile, go to the menu Image > Mode > Assign Color Profile and set it to RGB workspace(sRGB built-in).

To change the embedded profile, go to Image > Mode > Convert to Color Profile where you can choose a profile you already have loaded or load a new one from disk.

### ImageMagick

To remove the embedded profile, just run:

    $ convert -strip input_filename output_filename

Category:

- Image manipulation