Added a false color filter. Incorporated the shadows and highlights filter into the showcase.

Author: BradLarson

README.md

@@ -78,6 +78,10 @@ Documentation is generated from header comments using appledoc. To build the doc
   - *greenControlPoints*:
   - *blueControlPoints*: The tone curve takes in a series of control points that define the spline curve for each color component. These are stored as NSValue-wrapped CGPoints in an NSArray, with normalized X and Y coordinates from 0 - 1. The defaults are (0,0), (0.5,0.5), (1,1).
 
+- **GPUImageHighlightShadowFilter**: Adjusts the shadows and highlights of an image
+  - *shadows*: Increase to lighten shadows, from 0.0 to 1.0, with 0.0 as the default.
+  - *highlights*: Decrease to darken highlights, from 0.0 to 1.0, with 1.0 as the default.
+
 - **GPUImageColorInvertFilter**: Inverts the colors of an image
 
 - **GPUImageGrayscaleFilter**: Converts an image to grayscale (a slightly faster implementation of the saturation filter, without the ability to vary the color contribution)
@@ -86,6 +90,10 @@ Documentation is generated from header comments using appledoc. To build the doc
   - *intensity*: The degree to which the specific color replaces the normal image color (0.0 - 1.0, with 1.0 as the default)
   - *color*: The color to use as the basis for the effect, with (0.6, 0.45, 0.3, 1.0) as the default.
 
+- **GPUImageFalseColorFilter**: Uses the luminance of the image to mix between two user-specified colors
+  - *firstColor*: The first and second colors specify what colors replace the dark and light areas of the image, respectively. The defaults are (0.0, 0.0, 0.5) amd (1.0, 0.0, 0.0).
+  - *secondColor*: 
+
 - **GPUImageSepiaFilter**: Simple sepia tone filter
   - *intensity*: The degree to which the sepia tone replaces the normal image color (0.0 - 1.0, with 1.0 as the default)
 

examples/FilterShowcase/FilterShowcase/ShowcaseFilterListController.m

@@ -67,10 +67,12 @@ - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(N
 		case GPUIMAGE_EXPOSURE: cell.textLabel.text = @"Exposure"; break;
         case GPUIMAGE_RGB: cell.textLabel.text = @"RGB"; break;
         case GPUIMAGE_MONOCHROME: cell.textLabel.text = @"Monochrome"; break;
+        case GPUIMAGE_FALSECOLOR: cell.textLabel.text = @"False color"; break;
 		case GPUIMAGE_SHARPEN: cell.textLabel.text = @"Sharpen"; break;
 		case GPUIMAGE_UNSHARPMASK: cell.textLabel.text = @"Unsharp mask"; break;
 		case GPUIMAGE_GAMMA: cell.textLabel.text = @"Gamma"; break;
 		case GPUIMAGE_TONECURVE: cell.textLabel.text = @"Tone curve"; break;
+		case GPUIMAGE_HIGHLIGHTSHADOW: cell.textLabel.text = @"Highlights and shadows"; break;
 		case GPUIMAGE_HAZE: cell.textLabel.text = @"Haze"; break;
         case GPUIMAGE_HISTOGRAM: cell.textLabel.text = @"Histogram"; break;
 		case GPUIMAGE_THRESHOLD: cell.textLabel.text = @"Threshold"; break;

examples/FilterShowcase/FilterShowcase/ShowcaseFilterViewController.h

@@ -8,6 +8,7 @@ typedef enum {
     GPUIMAGE_EXPOSURE,
     GPUIMAGE_RGB,
     GPUIMAGE_MONOCHROME,
+    GPUIMAGE_FALSECOLOR,
     GPUIMAGE_SHARPEN,
     GPUIMAGE_UNSHARPMASK,
     GPUIMAGE_TRANSFORM,
@@ -16,6 +17,7 @@ typedef enum {
 	GPUIMAGE_MASK,
     GPUIMAGE_GAMMA,
     GPUIMAGE_TONECURVE,
+    GPUIMAGE_HIGHLIGHTSHADOW,
     GPUIMAGE_HAZE,
     GPUIMAGE_SEPIA,
     GPUIMAGE_COLORINVERT,

examples/FilterShowcase/FilterShowcase/ShowcaseFilterViewController.m

@@ -128,6 +128,13 @@ - (void)setupFilter;
             filter = [[GPUImageMonochromeFilter alloc] init];
             [(GPUImageMonochromeFilter *)filter setColor:(GPUVector4){0.0f, 0.0f, 1.0f, 1.f}];
         }; break;
+        case GPUIMAGE_FALSECOLOR:
+        {
+            self.title = @"False Color";
+            self.filterSettingsSlider.hidden = YES;
+            
+            filter = [[GPUImageFalseColorFilter alloc] init];
+		}; break;
         case GPUIMAGE_SATURATION:
         {
             self.title = @"Saturation";
@@ -229,6 +236,17 @@ - (void)setupFilter;
 
             filter = [[GPUImageToneCurveFilter alloc] init];
             [(GPUImageToneCurveFilter *)filter setBlueControlPoints:[NSArray arrayWithObjects:[NSValue valueWithCGPoint:CGPointMake(0.0, 0.0)], [NSValue valueWithCGPoint:CGPointMake(0.5, 0.5)], [NSValue valueWithCGPoint:CGPointMake(1.0, 0.75)], nil]];
+        }; break;
+        case GPUIMAGE_HIGHLIGHTSHADOW:
+        {
+            self.title = @"Highlights and Shadows";
+            self.filterSettingsSlider.hidden = NO;
+            
+            [self.filterSettingsSlider setValue:1.0];
+            [self.filterSettingsSlider setMinimumValue:0.0];
+            [self.filterSettingsSlider setMaximumValue:1.0];
+            
+            filter = [[GPUImageHighlightShadowFilter alloc] init];
         }; break;
 		case GPUIMAGE_HAZE:
         {
@@ -1074,8 +1092,8 @@ - (IBAction)updateFilterFromSlider:(id)sender;
         case GPUIMAGE_GAMMA: [(GPUImageGammaFilter *)filter setGamma:[(UISlider *)sender value]]; break;
         case GPUIMAGE_CROSSHATCH: [(GPUImageCrosshatchFilter *)filter setCrossHatchSpacing:[(UISlider *)sender value]]; break;
         case GPUIMAGE_POSTERIZE: [(GPUImagePosterizeFilter *)filter setColorLevels:round([(UISlider*)sender value])]; break;
-		case GPUIMAGE_HAZE: [(GPUImageHazeFilter *)filter setDistance:[(UISlider *)sender value]]; break;
-		case GPUIMAGE_THRESHOLD: [(GPUImageLuminanceThresholdFilter *)filter setThreshold:[(UISlider *)sender value]]; break;
+        case GPUIMAGE_HAZE: [(GPUImageHazeFilter *)filter setDistance:[(UISlider *)sender value]]; break;
+        case GPUIMAGE_THRESHOLD: [(GPUImageLuminanceThresholdFilter *)filter setThreshold:[(UISlider *)sender value]]; break;
         case GPUIMAGE_ADAPTIVETHRESHOLD: [(GPUImageAdaptiveThresholdFilter *)filter setBlurSize:[(UISlider*)sender value]]; break;
         case GPUIMAGE_DISSOLVE: [(GPUImageDissolveBlendFilter *)filter setMix:[(UISlider *)sender value]]; break;
         case GPUIMAGE_CHROMAKEY: [(GPUImageChromaKeyBlendFilter *)filter setThresholdSensitivity:[(UISlider *)sender value]]; break;
@@ -1093,6 +1111,7 @@ - (IBAction)updateFilterFromSlider:(id)sender;
         case GPUIMAGE_BULGE: [(GPUImageBulgeDistortionFilter *)filter setScale:[(UISlider *)sender value]]; break;
         case GPUIMAGE_SPHEREREFRACTION: [(GPUImageSphereRefractionFilter *)filter setRadius:[(UISlider *)sender value]]; break;
         case GPUIMAGE_TONECURVE: [(GPUImageToneCurveFilter *)filter setBlueControlPoints:[NSArray arrayWithObjects:[NSValue valueWithCGPoint:CGPointMake(0.0, 0.0)], [NSValue valueWithCGPoint:CGPointMake(0.5, [(UISlider *)sender value])], [NSValue valueWithCGPoint:CGPointMake(1.0, 0.75)], nil]]; break;
+        case GPUIMAGE_HIGHLIGHTSHADOW: [(GPUImageHighlightShadowFilter *)filter setHighlights:[(UISlider *)sender value]]; break;
         case GPUIMAGE_PINCH: [(GPUImagePinchDistortionFilter *)filter setScale:[(UISlider *)sender value]]; break;
         case GPUIMAGE_PERLINNOISE:  [(GPUImagePerlinNoiseFilter *)filter setScale:[(UISlider *)sender value]]; break;
         case GPUIMAGE_MOSAIC:  [(GPUImageMosaicFilter *)filter setDisplayTileSize:CGSizeMake([(UISlider *)sender value], [(UISlider *)sender value])]; break;

framework/GPUImage.xcodeproj/project.pbxproj

@@ -212,6 +212,10 @@
 		BCC1E66D152368130006EFA5 /* GPUImageCrosshatchFilter.h in Headers */ = {isa = PBXBuildFile; fileRef = BCC1E669152368130006EFA5 /* GPUImageCrosshatchFilter.h */; };
 		BCC1E66E152368130006EFA5 /* GPUImageCrosshatchFilter.m in Sources */ = {isa = PBXBuildFile; fileRef = BCC1E66A152368130006EFA5 /* GPUImageCrosshatchFilter.m */; };
 		BCC1E67C152368840006EFA5 /* GPUImageCGAColorspaceFilter.m in Sources */ = {isa = PBXBuildFile; fileRef = BCC1E67B152368840006EFA5 /* GPUImageCGAColorspaceFilter.m */; };
+		BCC46E5E15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.h in Headers */ = {isa = PBXBuildFile; fileRef = BCC46E5C15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.h */; };
+		BCC46E5F15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.m in Sources */ = {isa = PBXBuildFile; fileRef = BCC46E5D15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.m */; };
+		BCC46E6315BA095F005519B9 /* GPUImageFalseColorFilter.h in Headers */ = {isa = PBXBuildFile; fileRef = BCC46E6115BA095F005519B9 /* GPUImageFalseColorFilter.h */; };
+		BCC46E6415BA095F005519B9 /* GPUImageFalseColorFilter.m in Sources */ = {isa = PBXBuildFile; fileRef = BCC46E6215BA095F005519B9 /* GPUImageFalseColorFilter.m */; };
 		BCC93A0F1501D1BF00958B26 /* GPUImageFastBlurFilter.h in Headers */ = {isa = PBXBuildFile; fileRef = BCC93A0D1501D1BF00958B26 /* GPUImageFastBlurFilter.h */; };
 		BCC93A101501D1BF00958B26 /* GPUImageFastBlurFilter.m in Sources */ = {isa = PBXBuildFile; fileRef = BCC93A0E1501D1BF00958B26 /* GPUImageFastBlurFilter.m */; };
 		BCC93A1E1501E42F00958B26 /* GPUImageTwoPassFilter.h in Headers */ = {isa = PBXBuildFile; fileRef = BCC93A1C1501E42E00958B26 /* GPUImageTwoPassFilter.h */; };
@@ -466,6 +470,10 @@
 		BCC1E669152368130006EFA5 /* GPUImageCrosshatchFilter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GPUImageCrosshatchFilter.h; path = Source/GPUImageCrosshatchFilter.h; sourceTree = SOURCE_ROOT; };
 		BCC1E66A152368130006EFA5 /* GPUImageCrosshatchFilter.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = GPUImageCrosshatchFilter.m; path = Source/GPUImageCrosshatchFilter.m; sourceTree = SOURCE_ROOT; };
 		BCC1E67B152368840006EFA5 /* GPUImageCGAColorspaceFilter.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = GPUImageCGAColorspaceFilter.m; path = Source/GPUImageCGAColorspaceFilter.m; sourceTree = SOURCE_ROOT; };
+		BCC46E5C15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GPUImageHighlightShadowFilter.h; path = Source/GPUImageHighlightShadowFilter.h; sourceTree = SOURCE_ROOT; };
+		BCC46E5D15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = GPUImageHighlightShadowFilter.m; path = Source/GPUImageHighlightShadowFilter.m; sourceTree = SOURCE_ROOT; };
+		BCC46E6115BA095F005519B9 /* GPUImageFalseColorFilter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GPUImageFalseColorFilter.h; path = Source/GPUImageFalseColorFilter.h; sourceTree = SOURCE_ROOT; };
+		BCC46E6215BA095F005519B9 /* GPUImageFalseColorFilter.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = GPUImageFalseColorFilter.m; path = Source/GPUImageFalseColorFilter.m; sourceTree = SOURCE_ROOT; };
 		BCC93A0D1501D1BF00958B26 /* GPUImageFastBlurFilter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GPUImageFastBlurFilter.h; path = Source/GPUImageFastBlurFilter.h; sourceTree = SOURCE_ROOT; };
 		BCC93A0E1501D1BF00958B26 /* GPUImageFastBlurFilter.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = GPUImageFastBlurFilter.m; path = Source/GPUImageFastBlurFilter.m; sourceTree = SOURCE_ROOT; };
 		BCC93A1C1501E42E00958B26 /* GPUImageTwoPassFilter.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GPUImageTwoPassFilter.h; path = Source/GPUImageTwoPassFilter.h; sourceTree = SOURCE_ROOT; };
@@ -553,10 +561,6 @@
 		BC1B715D14F4AFFF00ACA2AB /* Color processing */ = {
 			isa = PBXGroup;
 			children = (
-				BCBCE9971595021B00E0ED33 /* GPUImageMonochromeFilter.h */,
-				BCBCE9981595021B00E0ED33 /* GPUImageMonochromeFilter.m */,
-				BEBE83B3155C092A00EEF8C3 /* GPUImageRGBFilter.h */,
-				BEBE83B4155C092A00EEF8C3 /* GPUImageRGBFilter.m */,
 				BC982B7714F098CC0001FF6F /* GPUImageBrightnessFilter.h */,
 				BC982B7814F098CC0001FF6F /* GPUImageBrightnessFilter.m */,
 				BCB6B833150400030041703B /* GPUImageExposureFilter.h */,
@@ -569,6 +573,14 @@
 				BC982B7D14F09F980001FF6F /* GPUImageGammaFilter.m */,
 				B81521A014F1BA6A00F105F8 /* GPUImageColorMatrixFilter.h */,
 				B81521A114F1BA6A00F105F8 /* GPUImageColorMatrixFilter.m */,
+				BEBE83B3155C092A00EEF8C3 /* GPUImageRGBFilter.h */,
+				BEBE83B4155C092A00EEF8C3 /* GPUImageRGBFilter.m */,
+				BCC46E5C15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.h */,
+				BCC46E5D15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.m */,
+				BCBCE9971595021B00E0ED33 /* GPUImageMonochromeFilter.h */,
+				BCBCE9981595021B00E0ED33 /* GPUImageMonochromeFilter.m */,
+				BCC46E6115BA095F005519B9 /* GPUImageFalseColorFilter.h */,
+				BCC46E6215BA095F005519B9 /* GPUImageFalseColorFilter.m */,
 				6D13DBE4151AA804000B23BA /* GPUImageHazeFilter.h */,
 				6D13DBE5151AA804000B23BA /* GPUImageHazeFilter.m */,
 				BCB5E7C014E4B6D400701302 /* GPUImageSepiaFilter.h */,
@@ -1019,6 +1031,8 @@
 				BCBCE9991595021B00E0ED33 /* GPUImageMonochromeFilter.h in Headers */,
 				BCBCE9D5159944AC00E0ED33 /* GPUImageBuffer.h in Headers */,
 				BCF6B41115A7849F00FC6F58 /* GPUImageOpacityFilter.h in Headers */,
+				BCC46E5E15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.h in Headers */,
+				BCC46E6315BA095F005519B9 /* GPUImageFalseColorFilter.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1246,6 +1260,8 @@
 				BCBCE99A1595021B00E0ED33 /* GPUImageMonochromeFilter.m in Sources */,
 				BCBCE9D6159944AC00E0ED33 /* GPUImageBuffer.m in Sources */,
 				BCF6B41215A7849F00FC6F58 /* GPUImageOpacityFilter.m in Sources */,
+				BCC46E5F15B9EFE8005519B9 /* GPUImageHighlightShadowFilter.m in Sources */,
+				BCC46E6415BA095F005519B9 /* GPUImageFalseColorFilter.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

framework/Source/GPUImage.h

@@ -104,4 +104,6 @@
 #import "GPUImageColorPackingFilter.h"
 #import "GPUImageSphereRefractionFilter.h"
 #import "GPUImageMonochromeFilter.h"
-#import "GPUImageOpacityFilter.h"
+#import "GPUImageOpacityFilter.h"
+#import "GPUImageHighlightShadowFilter.h"
+#import "GPUImageFalseColorFilter.h"

framework/Source/GPUImageFalseColorFilter.h

@@ -0,0 +1,15 @@
+#import "GPUImageFilter.h"
+
+@interface GPUImageFalseColorFilter : GPUImageFilter
+{
+    GLint firstColorUniform, secondColorUniform;
+}
+
+// The first and second colors specify what colors replace the dark and light areas of the image, respectively. The defaults are (0.0, 0.0, 0.5) amd (1.0, 0.0, 0.0).
+@property(readwrite, nonatomic) GPUVector4 firstColor;
+@property(readwrite, nonatomic) GPUVector4 secondColor;
+
+- (void)setFirstColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent;
+- (void)setSecondColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent;
+
+@end

framework/Source/GPUImageFalseColorFilter.m

@@ -0,0 +1,88 @@
+#import "GPUImageFalseColorFilter.h"
+
+NSString *const kGPUFalseColorFragmentShaderString = SHADER_STRING
+(
+ precision lowp float;
+ 
+ varying highp vec2 textureCoordinate;
+ 
+ uniform sampler2D inputImageTexture;
+ uniform float intensity;
+ uniform vec3 firstColor;
+ uniform vec3 secondColor;
+ 
+ const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
+ 
+ void main()
+ {
+     lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
+     float luminance = dot(textureColor.rgb, luminanceWeighting);
+     
+     gl_FragColor = vec4( mix(firstColor.rgb, secondColor.rgb, luminance), textureColor.a);
+ }
+);
+
+@implementation GPUImageFalseColorFilter
+
+@synthesize secondColor = _secondColor;
+@synthesize firstColor = _firstColor;
+
+- (id)init;
+{
+    if (!(self = [super initWithFragmentShaderFromString:kGPUFalseColorFragmentShaderString]))
+    {
+		return nil;
+    }
+    
+    firstColorUniform = [filterProgram uniformIndex:@"firstColor"];
+    secondColorUniform = [filterProgram uniformIndex:@"secondColor"];
+    
+	self.firstColor = (GPUVector4){0.0f, 0.0f, 0.5f, 1.0f};
+	self.secondColor = (GPUVector4){1.0f, 0.0f, 0.0f, 1.0f};
+    
+    return self;
+}
+
+
+#pragma mark -
+#pragma mark Accessors
+
+- (void)setFirstColor:(GPUVector4)newValue;
+{
+	_firstColor = newValue;
+	
+	[self setFirstColorRed:_firstColor.one green:_firstColor.two blue:_firstColor.three];
+}
+
+- (void)setSecondColor:(GPUVector4)newValue;
+{
+	_secondColor = newValue;
+	
+	[self setSecondColorRed:_secondColor.one green:_secondColor.two blue:_secondColor.three];
+}
+
+- (void)setFirstColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent;
+{
+    GLfloat filterColor[3];
+    filterColor[0] = redComponent;
+    filterColor[1] = greenComponent;
+    filterColor[2] = blueComponent;
+    
+    [GPUImageOpenGLESContext useImageProcessingContext];
+    [filterProgram use];
+    glUniform3fv(firstColorUniform, 1, filterColor);
+}
+
+- (void)setSecondColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent;
+{
+    GLfloat filterColor[3];
+    filterColor[0] = redComponent;
+    filterColor[1] = greenComponent;
+    filterColor[2] = blueComponent;
+    
+    [GPUImageOpenGLESContext useImageProcessingContext];
+    [filterProgram use];
+    glUniform3fv(secondColorUniform, 1, filterColor);
+}
+
+@end

framework/Source/GPUImageHighlightShadowFilter.h

@@ -1,15 +1,5 @@
 #import "GPUImageFilter.h"
 
-/**
- * This is an attempt to replicate CIHighlightShadowAdjust
- * 
- * 
- * @author Alaric Cole
- * @creationDate 07/10/12
- *
- */
-
-
 @interface GPUImageHighlightShadowFilter : GPUImageFilter
 {
     GLint shadowsUniform, highlightsUniform;

framework/Source/GPUImageMonochromeFilter.h

@@ -7,7 +7,7 @@
 
 @property(readwrite, nonatomic) CGFloat intensity;
 @property(readwrite, nonatomic) GPUVector4 color;
-//@property(readwrite, nonatomic) CIColor* color;
+
 - (void)setColorRed:(GLfloat)redComponent green:(GLfloat)greenComponent blue:(GLfloat)blueComponent;
 
 @end

framework/Source/GPUImageMonochromeFilter.m

@@ -2,46 +2,35 @@
 
 NSString *const kGPUMonochromeFragmentShaderString = SHADER_STRING
 (
-precision lowp float;
-
-varying highp vec2 textureCoordinate;
+ precision lowp float;
 
-uniform sampler2D inputImageTexture;
-uniform float intensity;
-uniform vec3 filterColor;
-
-const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
+ varying highp vec2 textureCoordinate;
 
-
+ uniform sampler2D inputImageTexture;
+ uniform float intensity;
+ uniform vec3 filterColor;
 
-void main()
-{
-	
-	
+ const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
+ 
+ void main()
+ {
 	//desat, then apply overlay blend
 	lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
 	float luminance = dot(textureColor.rgb, luminanceWeighting);
 
 	lowp vec4 desat = vec4(vec3(luminance), 1.0);
 
-	
-	
 	//overlay
 	lowp vec4 outputColor = vec4(
-						(desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))), 
-						(desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))), 
-						(desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))), 
-						1.0
-						);
+                                 (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
+                                 (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
+                                 (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
+                                 1.0
+                                 );
 
 	//which is better, or are they equal?
-	gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), 1.0 );
-	//gl_FragColor =  (intensity * outputColor) + ((1.0 - intensity) * textureColor);
-	
-	
-	
-
-}
+	gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
+ }
 );
 
 @implementation GPUImageMonochromeFilter

framework/Source/GPUImageRGBFilter.h

@@ -7,6 +7,7 @@
     GLint blueUniform;
 }
 
+// Normalized values by which each color channel is multiplied. The range is from 0.0 up, with 1.0 as the default.
 @property (readwrite, nonatomic) CGFloat red; 
 @property (readwrite, nonatomic) CGFloat green; 
 @property (readwrite, nonatomic) CGFloat blue;