roniemartinez / libqpsd

PSD (Photoshop Document) & PSB (Photoshop Big) Plugin for Qt/C++ (Qt4/Qt5)
GNU Lesser General Public License v2.1
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Lab to RGB color conversion discrepancies #8

Closed roniemartinez closed 11 years ago

roniemartinez commented 11 years ago

Hi!

I was able to obtain a copy of a PSB file from a Qt-Project username "asgohtals" (http://qt-project.org/forums/viewthread/22179/) in Lab color mode (with alpha color, aLab) and found out that the alpha channel is somewhat inverted (opaque = 0 and transparent = 255). I also found the reason why the Lab-to-RGB conversion algorithm cannot convert few pixels correctly since the calculated RGB falls outside the range 0-255.

Although libqpsd was able to render the image, there is a big discrepancy in color as shown in this screenshot (https://www.dropbox.com/s/3rbpkm5ddyrvcse/color%20difference.PNG). The image shown in photoshop software was sharper than the image rendered in a Qt-based image viewer I created.