Normalised image textures are now stored as 16 bit, rather than 8

bit. Was getting precision errors in clipping.

fsl/fslview/gl/gl21/glvolume_funcs.py

@@ -125,21 +125,18 @@ def updateShaderState(self):
     # range, but the shader needs them to be in image
     # texture value range (0.0 - 1.0). So let's scale 
     # them.
-    clipLow = opts.clippingRange[0]            * \
-        self.imageTexture.invVoxValXform[0, 0] + \
-        self.imageTexture.invVoxValXform[3, 0]
-    clipHigh = opts.clippingRange[1]           * \
-        self.imageTexture.invVoxValXform[0, 0] + \
-        self.imageTexture.invVoxValXform[3, 0] 
+    xform    = self.imageTexture.invVoxValXform
+    clipLow  = opts.clippingRange[0] * xform[0, 0] + xform[3, 0]
+    clipHigh = opts.clippingRange[1] * xform[0, 0] + xform[3, 0]
 
     gl.glUniform1f(self.clipLowPos,    clipLow)
     gl.glUniform1f(self.clipHighPos,   clipHigh)
     gl.glUniform1f(self.invertClipPos, opts.invertClipping)
-
-    # Bind transformation matrices to transform
-    # display coordinates to voxel coordinates,
-    # and to scale voxel values to colour map
-    # texture coordinates
+    
+    # Bind transformation matrix to transform
+    # from image texture values to voxel values,
+    # and and to scale said voxel values to
+    # colour map texture coordinates
     vvx = transform.concat(self.imageTexture.voxValXform,
                            self.colourTexture.getCoordinateTransform())
     vvx = np.array(vvx, dtype=np.float32).ravel('C')

fsl/fslview/gl/textures/imagetexture.py

@@ -227,7 +227,7 @@ class ImageTexture(texture.Texture):
         # for signed types.
 
         # Texture data type
-        if   self.__normalise:   texDtype = gl.GL_UNSIGNED_BYTE
+        if   self.__normalise:   texDtype = gl.GL_UNSIGNED_SHORT
         elif dtype == np.uint8:  texDtype = gl.GL_UNSIGNED_BYTE
         elif dtype == np.int8:   texDtype = gl.GL_UNSIGNED_BYTE
         elif dtype == np.uint16: texDtype = gl.GL_UNSIGNED_SHORT
@@ -246,28 +246,28 @@ class ImageTexture(texture.Texture):
         # Internal texture format
         if self.nvals == 1:
 
-            if   self.__normalise:   intFmt = gl.GL_LUMINANCE8
+            if   self.__normalise:   intFmt = gl.GL_LUMINANCE16
             elif dtype == np.uint8:  intFmt = gl.GL_LUMINANCE8
             elif dtype == np.int8:   intFmt = gl.GL_LUMINANCE8
             elif dtype == np.uint16: intFmt = gl.GL_LUMINANCE16
             elif dtype == np.int16:  intFmt = gl.GL_LUMINANCE16
 
         elif self.nvals == 2:
-            if   self.__normalise:   intFmt = gl.GL_LUMINANCE8_ALPHA8
+            if   self.__normalise:   intFmt = gl.GL_LUMINANCE16_ALPHA16
             elif dtype == np.uint8:  intFmt = gl.GL_LUMINANCE8_ALPHA8
             elif dtype == np.int8:   intFmt = gl.GL_LUMINANCE8_ALPHA8
             elif dtype == np.uint16: intFmt = gl.GL_LUMINANCE16_ALPHA16
             elif dtype == np.int16:  intFmt = gl.GL_LUMINANCE16_ALPHA16
 
         elif self.nvals == 3:
-            if   self.__normalise:   intFmt = gl.GL_RGB8
+            if   self.__normalise:   intFmt = gl.GL_RGB16
             elif dtype == np.uint8:  intFmt = gl.GL_RGB8
             elif dtype == np.int8:   intFmt = gl.GL_RGB8
             elif dtype == np.uint16: intFmt = gl.GL_RGB16
             elif dtype == np.int16:  intFmt = gl.GL_RGB16
             
         elif self.nvals == 4:
-            if   self.__normalise:   intFmt = gl.GL_RGBA8
+            if   self.__normalise:   intFmt = gl.GL_RGBA16
             elif dtype == np.uint8:  intFmt = gl.GL_RGBA8
             elif dtype == np.int8:   intFmt = gl.GL_RGBA8
             elif dtype == np.uint16: intFmt = gl.GL_RGBA16
@@ -385,8 +385,8 @@ class ImageTexture(texture.Texture):
             dmax = float(data.max())
             if dmax != dmin:
                 data = (data - dmin) / (dmax - dmin)
-            data = np.round(data * 255)
-            data = np.array(data, dtype=np.uint8)
+            data = np.round(data * 65535)
+            data = np.array(data, dtype=np.uint16)
             
         elif dtype == np.uint8:  pass
         elif dtype == np.int8:   data = np.array(data + 128,   dtype=np.uint8)