Png Image Did Not Start With Ihdr. Firstly the ihdr chunk which contains important metadata such as the width height of the image bit depth etc. Check under image mode.
A quick look at generate map cpp l682 png hpp l21 and image base hpp l23 suggest that similar issues may still be possible to trigger. Png file signature. Note that the png 1 0 and 1 1 specifications define only a single allowed value 0 for either the compression type or the filtering method.
The stored image is a valid png file of the sample depth indicated by ihdr.
If we were interested in whether the image is interlaced or what compression and filtering methods it uses we would use actual values instead of nulls for the last three arguments to png get ihdr. Windows 10 won t open png files i have tried opening with other programs but all say unable to open. Check under image mode. The png format is widely used especially on the web for saving images.
