#1134 image PNG Transparency file differences

[Tony Walsh]

Hi
I import a pdf as a background and want to apply images with transparency. Of the 2 files attached 'star' works fine but 'horse' becomes transparent to the point of disappearing. They are both generated in TCPDF using the same line of code. The client supplied the files as examples of the issue but I cannot find a difference in the file properties. Can anyone explain or suggest a solution been trying to find a solution but brick wall time.
Thanks in advance, Tony