Highlight Annotation Colors Are Not Read by FPDFPageObj_GetFillColor or FPDFPageObj_GetStrokeColor
nadeeshan 2021
Hello all,
I am working with PDF files that contain highlight annotations, and I noticed an issue when trying to extract the annotation color using PDFium.
Specifically:
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FPDFAnnot_GetColor does not return the color for these highlight annotations (The is expected as mentioned in the method). It returns false from the top of the method itself.
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Attempting to use FPDFPageObj_GetFillColor or FPDFPageObj_GetStrokeColor also does not help. These functions only return the alpha value of the annotation, while the RGB values are returned as zero.
Upon inspecting the PDF file, I observed the following:
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The annotation dictionary does include a /C property containing the RGB color values.
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However, the appearance stream (/AP) does not contain the color information for these annotations.
Because of this, the color defined in the /C property is not read by any of the available PDFium APIs, neither FPDFAnnot_GetColor nor the page object color functions (FPDFPageObj_GetFillColor, FPDFPageObj_GetStrokeColor). I would appreciate it if anyone could point me to the recommended way to handle this situation. Thank you in advance!
Here are the annotation objects and the file.
Annotation Object
<< /AP << /N 23 0 R >> /C [ 1 0.384308 0 ] /CA 0.399994 /CreationDate D:20251012000047+05'30' /F 4 /M D:20251012000047+05'30' /NM 95ebcf19-0239-4983-ae52-424a30a70fc6 /P 22 0 R /Popup 61 0 R /QuadPoints [ 74.8 698.794 516.429 698.794 74.8 674.746 516.429 674.746 56.8 678.094 289.539 678.094 56.8 654.046 289.539 654.046 ] /Rect [ 56.0485 653.295 517.18 699.545 ] /Subj Highlight /Subtype /Highlight /T Folia Product /Ty
Appearance Stream
The annotation file -