diff --git a/sent.c b/sent.c
index 0da2bff..d92cf3b 100644
--- a/sent.c
+++ b/sent.c
@@ -282,27 +282,66 @@ ffprepare(Image *img)
 	img->state |= SCALED;
 }
 
+static unsigned char double_to_uchar_clamp255(double dbl)
+{
+	dbl = round(dbl);
+
+	return
+		(dbl < 0.0)   ? 0 :
+		(dbl > 255.0) ? 255 : (unsigned char)dbl;
+}
+
+static int int_clamp(int integer, int lower, int upper)
+{
+	if (integer < lower)
+		return lower;
+	else if (integer >= upper)
+		return upper - 1;
+	else
+		return integer;
+}
+
 void
 ffscale(Image *img)
 {
-	unsigned int x, y;
-	unsigned int width = img->ximg->width;
-	unsigned int height = img->ximg->height;
-	char* newBuf = img->ximg->data;
-	unsigned char* ibuf;
-	unsigned int jdy = img->ximg->bytes_per_line / 4 - width;
-	unsigned int dx = (img->bufwidth << 10) / width;
-
-	for (y = 0; y < height; y++) {
-		unsigned int bufx = img->bufwidth / width;
-		ibuf = &img->buf[y * img->bufheight / height * img->bufwidth * 3];
-
-		for (x = 0; x < width; x++) {
-			*newBuf++ = (ibuf[(bufx >> 10)*3+2]);
-			*newBuf++ = (ibuf[(bufx >> 10)*3+1]);
-			*newBuf++ = (ibuf[(bufx >> 10)*3+0]);
+	const unsigned width = img->ximg->width;
+	const unsigned height = img->ximg->height;
+	unsigned char* newBuf = (unsigned char*)img->ximg->data;
+	const unsigned jdy = img->ximg->bytes_per_line / 4 - width;
+
+	const double x_scale = ((double)img->bufwidth/(double)width);
+	const double y_scale = ((double)img->bufheight/(double)height);
+
+	for (unsigned y = 0; y < height; ++y) {
+		const double old_y = (double)y * y_scale;
+		const double y_factor = ceil(old_y) - old_y;
+		const int old_y_int_0 = int_clamp((int)floor(old_y), 0, img->bufheight);
+		const int old_y_int_1 = int_clamp((int)ceil(old_y), 0, img->bufheight);
+
+		for (unsigned x = 0; x < width; ++x) {
+			const double old_x = (double)x * x_scale;
+			const double x_factor = ceil(old_x) - old_x;
+			const int old_x_int_0 = int_clamp((int)floor(old_x), 0, img->bufwidth);
+			const int old_x_int_1 = int_clamp((int)ceil(old_x), 0, img->bufwidth);
+
+			const unsigned c00_pos = 3*((old_x_int_0) + ((old_y_int_0)*img->bufwidth));
+			const unsigned c01_pos = 3*((old_x_int_0) + ((old_y_int_1)*img->bufwidth));
+			const unsigned c10_pos = 3*((old_x_int_1) + ((old_y_int_0)*img->bufwidth));
+			const unsigned c11_pos = 3*((old_x_int_1) + ((old_y_int_1)*img->bufwidth));
+
+			for (int i = 2; i >= 0 ; --i) {
+				const unsigned char c00 = img->buf[c00_pos + i];
+				const unsigned char c01 = img->buf[c01_pos + i];
+				const unsigned char c10 = img->buf[c10_pos + i];
+				const unsigned char c11 = img->buf[c11_pos + i];
+
+				const double x_result_0 = (double)c00*x_factor + (double)c10*(1.0 - x_factor);
+				const double x_result_1 = (double)c01*x_factor + (double)c11*(1.0 - x_factor);
+				const double result = x_result_0*y_factor + x_result_1*(1.0 - y_factor);
+
+				*newBuf++ = double_to_uchar_clamp255(result);
+			}
 			newBuf++;
-			bufx += dx;
 		}
 		newBuf += jdy;
 	}