I took an image and simply changed the canvass size so that I could create more space.

After increasing the canvass size with clear/alpha I exported to both .png and .jpg and set for the highest standards.

In both cases the image was distorted.


enter image description here


enter image description here

Please note I used the highest quality for exporting. I used no compression when creating the PNG.


I noticed that simply trying to fill the image with white does not work correctly. It is filled with a strange Orange color.

Also "flattening the image" , not sure what this means as the image only has one layer in GIMP creates this strange Orange color background.

1 Answer 1


Your image has indexed colors. If you try to add white to it, you get something from the palette and there's no white. Change the image mode at first to RGB to get free hands for coloring.

If you delete the transparency, the anti-aliasing vanishes and you get a pixelated look. Anti-aliasing stays if you are in RGB mode and remove the alpha channel. The current background color is taken into use.

See the next screenshot:

enter image description here

The image mode is changed to RGB, a white layer is inserted as a new layer and moved to the background in the layers panel. This can be flattened if you expect a single layer image. You can also convert it (=the flattened version) to indexed mode without problems if you allow enough colors.

  • So how do I fix it?
    – Sun - FE
    May 3, 2019 at 0:23
  • @Sun-FE You cannot fix what you have already deleted. Take the original. Start with Image > Mode >RGB. Increase now canvas size. Then goto Layer > New Layer, fill with white
    – user82991
    May 3, 2019 at 0:27
  • Thanks. Curious as to why I have not come upon this issue before. Is it odd to grab PNGs off the internet and for them not to be in "RGB mode"?
    – Sun - FE
    May 3, 2019 at 1:04
  • 1
    Color-indexed PNGs exist... They aren't too frequent because there isn't that much size gain. However you must be using Gimp 2.8, which processes indexed PNG like GIFs. Gimp 2.10 seems to have improved this.
    – xenoid
    May 3, 2019 at 6:45

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