1 files changed, 74 insertions, 0 deletions
diff --git a/Imaging/libImaging/Matrix.c b/Imaging/libImaging/Matrix.c
new file mode 100644
index 0000000..08010a7
--- /dev/null
+++ b/Imaging/libImaging/Matrix.c
@@ -0,0 +1,74 @@
+/*
+ * The Python Imaging Library
+ * $Id: Matrix.c 2134 2004-10-06 08:55:20Z fredrik $
+ *
+ * colour and luminance matrix transforms
+ *
+ * history:
+ * 1996-05-18 fl:   created (brute force implementation)
+ *
+ * Copyright (c) Fredrik Lundh 1996.
+ * Copyright (c) Secret Labs AB 1997.
+ *
+ * See the README file for information on usage and redistribution.
+ */
+
+
+#include "Imaging.h"
+
+
+#define	CLIPF(v) ((v <= 0.0) ? 0 : (v >= 255.0F) ? 255 : (UINT8) v)
+
+
+Imaging
+ImagingConvertMatrix(Imaging im, const char *mode, float m[])
+{
+    Imaging imOut;
+    int x, y;
+
+    /* Assume there's enough data in the buffer */
+    if (!im)
+	return (Imaging) ImagingError_ModeError();
+
+    if (strcmp(mode, "L") == 0 && im->bands == 3) {
+
+	imOut = ImagingNew("L", im->xsize, im->ysize);
+	if (!imOut)
+	    return NULL;
+
+	for (y = 0; y < im->ysize; y++) {
+	    UINT8* in = (UINT8*) im->image[y];
+	    UINT8* out = (UINT8*) imOut->image[y];
+
+	    for (x = 0; x < im->xsize; x++) {
+		float v = m[0]*in[0] + m[1]*in[1] + m[2]*in[2] + m[3] + 0.5;
+		out[x] = CLIPF(v);
+		in += 4;
+	    }
+	}
+
+    } else if (strlen(mode) == 3 && im->bands == 3) {
+
+	imOut = ImagingNew(mode, im->xsize, im->ysize);
+	if (!imOut)
+	    return NULL;
+
+	for (y = 0; y < im->ysize; y++) {
+	    UINT8* in = (UINT8*) im->image[y];
+	    UINT8* out = (UINT8*) imOut->image[y];
+
+	    for (x = 0; x < im->xsize; x++) {
+		float v0 = m[0]*in[0] + m[1]*in[1] +  m[2]*in[2] +  m[3] + 0.5;
+		float v1 = m[4]*in[0] + m[5]*in[1] +  m[6]*in[2] +  m[7] + 0.5;
+		float v2 = m[8]*in[0] + m[9]*in[1] + m[10]*in[2] + m[11] + 0.5;
+		out[0] = CLIPF(v0);
+		out[1] = CLIPF(v1);
+		out[2] = CLIPF(v2);
+		in += 4; out += 4;
+	    }
+	}
+    } else
+	return (Imaging) ImagingError_ModeError();
+
+    return imOut;
+}