Photoshop psd spec "psfl"

Hi and thanks for your pointers.

I took a look at python psd-tools before - they seem to just skip this part.

Then - I took look at libpsd .. they shift-right the resulting uint32 for 8 bits.

// 4 bytes each for XYZ color

data->x_color = psd_stream_get_int(context) >> 8;

data->y_color = psd_stream_get_int(context) >> 8;

data->z_color = psd_stream_get_int(context) >> 8;

However when I do so I'm getting XYZ=(51,91,15) for RGB=(0.0,1.0,0.0).

As "Test Screen Name" mentions the value could be fixed point - so I gave that a try.

There are several options to represent a fixed point number in 32 bits. I've tried an online converter

Fixed Point Converter | Byte Craft Limited - here are the results.

This is the value I'm trying to read out - 100% green.

-> RGB (0.0,1.0,0.0)

With lindbloom's converter (sRGB and D50 white point) I get:

X 0.385065

Y 0.716879

Z 0.097105

The fixed point converter yields these:

format = "fract8"

X 0x00003320 -> 0.3984375

Y 0x00005BC3 -> 0.7109375

Z 0x00000F0F -> 0.1171875

format = "_Fract"

X 0x00003320 -> 0.3994140625

Y 0x00005BC3 -> 0.716888427734375

Z 0x00000F0F -> 0.117645263671875

format = fract24

X 0x00003320 -> 0.3994140625

Y 0x00005BC3 -> 0.716888427734375

Z 0x00000F0F -> 0.117645263671875

Pretty close - I'm not sure if there's some difference in the color space conversion or if it's another fixed point format.

Any ideas why they just didn't put an ordinary float32 there if there is plenty of space!?

I'll continue playing with different fixed point representations and see what I'll get.

Thanks again for your hints (JJMack,Test Screen Name), these were very helpful.