writing tEXt chunk data to PNG

Question

Is it impossible to write tEXt chunk data to PNG on iOS?

I successfully read the chunk data and modified it to add tEXt data to the chunk and saved it as an image in Gallery,

But the tEXt data keeps disappearing when I read the chunk data from the image in the Gallery.

Does iOS prevent preserving tEXt data when saving an image to Gallery?

449

Posted by

profileName

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Answer 1

Where are you placing your chunk(s). ie after the IHDR chunk and before the IDAT chunk(s), in front of other chunks, etc.?

Are you adding them just before saving the data to a file? How are you saving the data (ie pngData(), .writeTo(), etc...)

there could a number of reasons... please post your code

Posted by

blaine l

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