makeImageData function sometimes output a img with black border


So you are now using 1.8.23. Could you please use 1.8.36 instead? There have been bug fixes since 1.8.23.

What is your call to Diagram.makeImageData?

Do you have any clue why the Canvas sizes are different on their machines? Could you debug on their machines to see whether there is any CSS that is affecting the Canvas element or any Div element within the Diagram’s Div element?

var img = myDiagram.makeImageData({
      scale: 1,
      background: "#fff",
      maxSize: new go.Size(40000, 40000)

I am also trying to get this div size


How large are the problem images? 40000x40000 is probably too large for a maximum – that’s about 640MB in memory!


some time chart has to many entities and then image become too big
and default max size is shorted then image
but i have set permission on export image if nodes are more then 400 then user is not able to make image but black area in image is coming in every size of image as i show in my post that image is too large


OK, I did not know if your images had been clipped in the post.

Do you have the problem on macOS and Windows?


Did not tested on macOS yet but on Windows we have same problem


OK, thanks for testing on different machines and browsers.

Did you make any progress investigating this possibility?


Hi after long wasting of time i got the problem
My tester team was testing my app for different resolutions by changing browser’s zoom level
black area images are exported with browser’s zoom level out
i got this problem when i was debugging for different size of canvas
I am really sorry this is not gojs bug
but after got this problem i try to regenerate this image with black area but with zoom out even you reload the page with zoom out image should be with black area
really don’t know why this happen
All your responses are appreciable
Thank you very much