Comment Re:Vector Graphics (Score 2, Interesting) 160
This is actually a bigger issue than most people realize. All of the charts in Excel and PowerPoint are embedded as EMF files, which indeed are poorly documented.
But even worse than WMF/EMF is the EMF+ Dual format used in recent versions of Office. It is an almost completely undocumented format that hides GDI+ commands within EMF comment records in parallel with the normal GDI-based records. Because only Microsoft knows the format of the secret comment records, only it can leverage them to produce higher quality results by rendering via GDI+. Applications which understand EMF will skip over the comments, oblivious to the secret data (which is perhaps why awareness of this issue isn't more widespread). Knowledge of these records would be especially useful when converting to other vector formats such as SVG or PDF.
Many people have written to Microsoft in an attempt to get EMF+ documented, so far to no avail (and it was introduced no later than Office 2000).
I recently wrote about this issue in more depth.
But even worse than WMF/EMF is the EMF+ Dual format used in recent versions of Office. It is an almost completely undocumented format that hides GDI+ commands within EMF comment records in parallel with the normal GDI-based records. Because only Microsoft knows the format of the secret comment records, only it can leverage them to produce higher quality results by rendering via GDI+. Applications which understand EMF will skip over the comments, oblivious to the secret data (which is perhaps why awareness of this issue isn't more widespread). Knowledge of these records would be especially useful when converting to other vector formats such as SVG or PDF.
Many people have written to Microsoft in an attempt to get EMF+ documented, so far to no avail (and it was introduced no later than Office 2000).
I recently wrote about this issue in more depth.
