diff --git a/README.md b/README.md
index 7b9cba8..ac0fa8c 100644
--- a/README.md
+++ b/README.md
@@ -89,7 +89,7 @@ Image names are `audiofile-x.png`, where `x` is:
 
 Currently there are 3 available enhancements:
 
- - `c` for contrast equalise, on by default
+ - `c` for calibration, on by default
  - `t` for crop telemetry, on by default, only has effects on raw images
  - `h` for histogram equalise, make the darkest color black and the brightest white
 
@@ -97,7 +97,7 @@ Currently there are 3 available enhancements:
 
 `aptdec -d images -i ab *.wav`
 
-This will process all `.wav` files in the current directory, generate equalised channel A and B images and put them in the `images` directory.
+This will process all `.wav` files in the current directory, generate calibrated channel A and B images and put them in the `images` directory.
 
 ## Further reading
 
diff --git a/image.c b/image.c
index fd7d0c9..c4fafae 100644
--- a/image.c
+++ b/image.c
@@ -83,8 +83,8 @@ void histogramEqualise(float **prow, int nrow, int offset, int width){
 			prow[y][x+offset] = (prow[y][x+offset]-min) / (max-min) * 255;
 }
 
-// Brightness equalise, including telemetry
-void equalise(float **prow, int nrow, int offset, int width, int telestart, rgparam regr[30]){
+// Brightness calibrate, including telemetry
+void calibrateBrightness(float **prow, int nrow, int offset, int width, int telestart, rgparam regr[30]){
 	offset -= SYNC_WIDTH+SPC_WIDTH;
 
 	for (int n = 0; n < nrow; n++) {
@@ -126,7 +126,7 @@ void equalise(float **prow, int nrow, int offset, int width, int telestart, rgpa
 }
 
 // Get telemetry data for thermal calibration/equalization
-int calibrate(float **prow, int nrow, int offset, int width, int contrastEqualise) {
+int calibrate(float **prow, int nrow, int offset, int width, int calibrate) {
     double teleline[3000] = { 0.0 };
     double wedge[16];
     rgparam regr[30];
@@ -236,7 +236,7 @@ int calibrate(float **prow, int nrow, int offset, int width, int contrastEqualis
     }
     nbtele = k;
 
-	if(contrastEqualise) equalise(prow, nrow, offset, width, telestart, regr);
+	if(calibrate) calibrateBrightness(prow, nrow, offset, width, telestart, regr);
 
     return(channel + 1);
 }
diff --git a/main.c b/main.c
index a03a448..46b70dc 100644
--- a/main.c
+++ b/main.c
@@ -224,10 +224,10 @@ static void distrib(char *filename, float **prow, int nrow) {
 			distrib[y][x] = distrib[y][x] / max * 255;
 
 
-	ImageOut(filename, "Value distribution", distrib, 256, 256, 0, NULL, 0);
+	ImageOut(filename, "Brightness distribution", distrib, 256, 256, 0, NULL, 0);
 }
 
-extern int calibrate(float **prow, int nrow, int offset, int width, int contrastEqualise);
+extern int calibrate(float **prow, int nrow, int offset, int width, int calibrate);
 extern void histogramEqualise(float **prow, int nrow, int offset, int width);
 extern void temperature(float **prow, int nrow, int ch, int offset);
 extern int Ngvi(float **prow, int nrow);
@@ -242,7 +242,7 @@ static void usage(void) {
     printf("Aptdec [options] audio files ...\n"
 	"Options:\n"
 	" -e [c|t]       Enhancements\n"
-	"     c: Contrast equalise\n"
+	"     c: Contrast calibration\n"
 	"     t: Crop telemetry\n"
 	"     h: Histogram equalise\n"
 	" -i [r|a|b|c|t] Output image type\n"
@@ -371,11 +371,12 @@ int main(int argc, char **argv) {
 			ImageOut(pngfilename, "Temperature", prow, nrow, CH_WIDTH, CHB_OFFSET, (png_color*)TempPalette, 0);
 		}
 
-		// Run the contrast equalise here because the temperature calibration requires raw data
-		// Also layered & false color images both need brightness equalization
+		// Run the brightness calibration here because the temperature calibration requires raw data
+		// Layered & false color images both also need brightness calibration
 		if(CONTAINS(enchancements, 'c') || CONTAINS(enchancements, 'h') || CONTAINS(imgopt, 'l') || CONTAINS(imgopt, 'c'))
 			calibrate(prow, nrow, CHA_OFFSET, CH_WIDTH+TELE_WIDTH+SYNC_WIDTH+SPC_WIDTH+CH_WIDTH, 1);
 
+		// Histogram equalise
 		if(CONTAINS(enchancements, 'h')){
 			histogramEqualise(prow, nrow, CHA_OFFSET, CH_WIDTH);
 			histogramEqualise(prow, nrow, CHB_OFFSET, CH_WIDTH);