macOS Bug with ImageIO?

[kainjow]

I think I found a bug with ImageIO but not sure.

Go to http://www.apple.com/pr/bios and download Steve Jobs' photo.
Open the tif in Preview, and Save As a JPEG (the image quality doesn't matter). Now you'll see the colors will get all funky.

I actually found this out originally by testing some ImageIO code. All I did was open the image via CGImageSource, get the CGImage from it, and add it to a CGImageDestination of type JPEG. I then viewed in Preview, and same thing.

However, if I draw the image into a *new* CGImage (CGBitmapContext), it works.

Should report a bug?

 

[gnasher729]

I think I found a bug with ImageIO but not sure.

Go to http://www.apple.com/pr/bios and download Steve Jobs' photo.
Open the tif in Preview, and Save As a JPEG (the image quality doesn't matter). Now you'll see the colors will get all funky.

I actually found this out originally by testing some ImageIO code. All I did was open the image via CGImageSource, get the CGImage from it, and add it to a CGImageDestination of type JPEG. I then viewed in Preview, and same thing.

However, if I draw the image into a *new* CGImage (CGBitmapContext), it works.

Should report a bug?

Of course you should report a bug. If you don't report it, it won't get fixed. If you report it, well

I'd report it both an www.apple.com/feedback if it is a bug in the Preview application, and as an ImageIO bug through your ADC account.

 

[kainjow]

Will do. It's sometimes hard to know when you've found a bug or you're just not using an API correctly. But in this case I was pretty sure since I could duplicate it with Preview.

I seem to be finding several Quartz-related bugs recently.