Description: In LibreOffice Impress, going to File->Export and then choosing the file extension to be png results in an image with color reversal, i.e., that is the negative of the actual colors on the Impress file. White becomes black, etc. This does not happen when exporting to a jpg. Actual Results: Create a LibreOffice Impress file. Go to File -> Export and when the file explorer pop-up window appears, choose the file extension to be png using the drop-down. Expected Results: The saved png file will be the negative, color-wise, of the original Impress file. Reproducible: Always User Profile Reset: No Additional Info: Version: 7.2.2.2 (x64) / LibreOffice Community Build ID: 02b2acce88a210515b4a5bb2e46cbfb63fe97d56 CPU threads: 12; OS: Windows 10.0 Build 19044; UI render: Skia/Raster; VCL: win Locale: en-US (en_US); UI: en-US Calc: CL
I cannot confirm it. Tested with Version: 7.5.0.0.alpha0+ (X86_64) / LibreOffice Community Build ID: 17dfc9a9da009cc23d2222e3fb4e2cef9c97d581 CPU threads: 8; OS: Windows 10.0 Build 19045; UI render: Skia/Raster; VCL: win Locale: de-DE (en_US); UI: en-US Calc: CL threaded Do you have the problem with every presentation or only with a specific presentation. If latter, please attach the presentation. Do you use odp file format or do you use pptx?
Created attachment 183658 [details] odp Impress file used to generate the png
Created attachment 183659 [details] the png generated from the odp Impress file
Created attachment 183660 [details] screen shot showing how png appears when viewed in Windows 10 Photos This is a screen shot of how the png image from the Impress odp file appears when viewed with Windows 10 Photos.
Created attachment 183661 [details] screen shot showing how png appears when viewed in Irfanview This is a screen shot showing how the png image created from the odp file appears when viewed with Irfanview, a popular image software program. You can see the white background is changed to black.
I am using the odp file format in Impress, never the pptx. I have attached the odp file, the png generated from it, and two screen shots showing how the png image appears when viewed in two popular image software programs: Windows 10 Photos which came with my Windows 10 system, and Irfanview, a widely used free image software program. You can see in both screen shots that the background color is changed from white to black. I still believe the problem is with LibreOffice's generation of the png file. It is hard to believe that both Windows 10 Photos and Irfanview have bugs causing this. It is true that when viewed in Windows 10 Paint the background color is correct. But the png file should display correctly in all standard image programs, not just some of them. Something is wrong with this png.
To answer the question "Do you have the problem with every presentation or only with a specific presentation. If latter, please attach the presentation." I have this problem every time I save an Impress odp slide as a png. It has happened multiple times with different Impress odp files.
It is not a problem of color-inversion, but it is the problem how transparency is rendered in a viewer. Some draw it black: Irvanview Some draw it white: Windows Paint, PaintShopPro Some draw it checkered: paint.net Some show it transparent so that the application background is visible: Seamonkey, Google Chrome Some viewers allow the user to determine how transparent parts are rendered. If you disable transparency in the export dialog, you get a white background in just this exported image. Or you set the master slide background explicitly to White color instead of None. Then no exported image is transparency. It depends on whether you need the transparency in the exported image. JPEG is not affected, because JPEG cannot use transparency at all.