Related
This is a beginner question about usage of HLSL shaders in MonoGame. I have a texture with a multiple areas of different colors and want to highlight borders of such areas.
Preparing sprites batch:
batch.Begin( SpriteSortMode.Deferred,
BlendState.AlphaBlend,
SamplerState.LinearWrap,
null, null, bordersEffect,
viewer.Camera.GetViewMatrix());
In the bordersEffect I am loading my .fx with the following:
Texture2D SpriteTexture;
float2 SpriteTextureSize;
sampler2D SpriteTextureSampler = sampler_state
{
Texture = <SpriteTexture>;
};
struct VertexShaderOutput
{
float4 Position : SV_POSITION;
float4 Color : COLOR0;
float2 TextureCoordinates : TEXCOORD0;
};
float4 MainPS(VertexShaderOutput input) : COLOR
{
float offx = 1.0 / SpriteTextureSize[0];
float offy = 1.0 / SpriteTextureSize[1];
float4 pixelColor = tex2D(SpriteTextureSampler, input.TextureCoordinates);
float4 topLeft = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(-offx, -offy));
float4 top = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(0, -offy));
float4 topRight = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(offx, -offy));
float4 left = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(-offx, 0));
float4 right = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(offx, 0));
float4 bottomLeft = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(-offx, offy));
float4 bottom = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(0, offy));
float4 bottomRight = tex2D(SpriteTextureSampler, input.TextureCoordinates + float2(offx, offy));
if (any(pixelColor != topLeft) || any(pixelColor != top) || any(pixelColor != topRight) ||
any(pixelColor != left) || any(pixelColor != right) ||
any(pixelColor != bottomLeft) || any(pixelColor != bottom) || any(pixelColor != bottomRight))
{
// this is a border pixel
return pixelColor + float4(0.1, 0.1, 0.1, 0);
}
return pixelColor * input.Color;
}
technique SpriteDrawing
{
pass P0
{
PixelShader = compile PS_SHADERMODEL MainPS();
}
};
This highlights border pixels, but when I zoom in the camera, the edge between color areas is blended but the edge of the highlight and the color itself is not blended.
edges not blended
What am I missing?
I need to center it on a 2D texture when adjusting fit/fill texture in the view, but I can't configure uv coords.
Original image
When adjust fill, show the first part of the image not the center:
Fill image
when adjust fit, not get the correct center:
Fit image
float2 adjustPos(float2 size,
float2 uv) {
uv.x /= size.x;
uv.y /= size.y;
uv.y = 1.0f - uv.y;
return uv;
}
float2 scaleTexture(texture2d<float, access::sample> tex2d,
float2 size,
float2 uv,
int mode) {
int width = tex2d.get_width();
int height = tex2d.get_height();
float widthRatio = size.x/width;
float heightRatio = size.y/height;
float2 pos;
if (mode == 0) { // Aspect Fit
int2 newSize = int2(width*widthRatio, height*widthRatio);
pos = adjustPos(float2(newSize), uv);
float y = (uv.y/size.y) / 2.0;
y = y-pos.y;
y = 1.0f-y;
pos.y = y;
} else if (mode == 1) { // Aspect Fill
int2 newSize = int2(width*heightRatio, height*heightRatio);
pos = adjustPos(float2(newSize), uv);
if (newSize.x != size.x) {
pos.x = 0.5f + ((pos.x - 0.5f) * (1.0f - (heightRatio/100)));
}
} else {
float scale = min(widthRatio, heightRatio);
int2 newSize = int2(width*scale, height*scale);
pos = adjustPos(float2(newSize), uv);
}
return pos;
}
You can use this shader and customize it as per your requirements. This solution will let you make a texture fit fill within a given size.
The following metal shader takes a texture, an output size, expected content mode, and returns a fit/fill image within the given size.
fragment float4 fragment_aspect_fitfill(
VertexOut vertexIn [[stage_in]],
texture2d<float, access::sample> sourceTexture [[texture(0)]],
sampler sourceSampler [[sampler(0)]],
constant float2 &size [[ buffer(0) ]],
constant float &contentMode [[ buffer(1) ]])
{
float2 uv = vertexIn.textureCoordinate;
//Calculate Aspect Ration for both Texture and Expected output texture
float textureAspect = (float)sourceTexture.get_width() / (float)sourceTexture.get_height();
float frameAspect = (float)size.x / (float)size.y;
float scaleX = 1, scaleY = 1;
float textureFrameRatio = textureAspect / frameAspect;
bool portraitTexture = textureAspect < 1;
bool portraitFrame = frameAspect < 1;
// Content mode 0 is for aspect Fill, 1 is for Aspect Fit
if(contentMode == 0.0) {
if(portraitFrame)
scaleX = 1.f / textureFrameRatio;
else
scaleY = textureFrameRatio;
} else if(contentMode == 1.0) {
if(portraitFrame)
scaleY = textureFrameRatio;
else
scaleX = 1.f / textureFrameRatio;
}
float2 textureScale = float2(scaleX, scaleY);
float2 vTexCoordinate = textureScale * (uv - 0.5) + 0.5;
return sourceTexture.sample(sourceSampler, vTexCoordinate);
}
*Tips: This MSL uses some struct of MetalPetal.
I have just finished porting my engine from XNA to SharpDX(DX11).
Everything is going really well and I have conquered most of my issues without having to ask for help until now and I'm really stuck, maybe I just need another set of eye to look over my code idk but here it is.
I'm implementing tile based lighting (point lights only for now), I'm basing my code off the Intel sample because it's not as messy as the ATI one.
So my problem is that the lights move with the camera, I have looked all over the place to find a fix and I have tried everything (am I crazy?).
I just made sure all my normal and light vectors are in view space and normalized (still the same).
I have tried with the inverse View, inverse Projection, a mix of the both and a few other bits from over the net but I can't fix it.
So here is my CPU code:
Dim viewSpaceLPos As Vector3 = Vector3.Transform(New Vector3(pointlight.PosRad.X, pointlight.PosRad.Y, pointlight.PosRad.Z), Engine.Camera.EyeTransform)
Dim lightMatrix As Matrix = Matrix.Scaling(pointlight.PosRad.W) * Matrix.Translation(New Vector3(pointlight.PosRad.X, pointlight.PosRad.Y, pointlight.PosRad.Z))
Here is my CS shader code:
[numthreads(GROUP_WIDTH, GROUP_HEIGHT, GROUP_DEPTH)]
void TileLightingCS(uint3 dispatchThreadID : SV_DispatchThreadID, uint3 GroupID : SV_GroupID, uint3 GroupThreadID : SV_GroupThreadID)
{
int2 globalCoords = dispatchThreadID.xy;
uint groupIndex = GroupThreadID.y * GROUP_WIDTH + GroupThreadID.x;
float minZSample = FrameBufferCamNearFar.x;
float maxZSample = FrameBufferCamNearFar.y;
float2 gbufferDim;
DepthBuffer.GetDimensions(gbufferDim.x, gbufferDim.y);
float2 screenPixelOffset = float2(2.0f, -2.0f) / gbufferDim;
float2 positionScreen = (float2(globalCoords)+0.5f) * screenPixelOffset.xy + float2(-1.0f, 1.0f);
float depthValue = DepthBuffer[globalCoords].r;
float3 positionView = ComputePositionViewFromZ(positionScreen, Projection._43 / (depthValue - Projection._33));
// Avoid shading skybox/background or otherwise invalid pixels
float viewSpaceZ = positionView.z;
bool validPixel = viewSpaceZ >= FrameBufferCamNearFar.x && viewSpaceZ < FrameBufferCamNearFar.y;
[flatten] if (validPixel)
{
minZSample = min(minZSample, viewSpaceZ);
maxZSample = max(maxZSample, viewSpaceZ);
}
// How many total lights?
uint totalLights, dummy;
InputBuffer.GetDimensions(totalLights, dummy);
// Initialize shared memory light list and Z bounds
if (groupIndex == 0)
{
sTileNumLights = 0;
sMinZ = 0x7F7FFFFF; // Max float
sMaxZ = 0;
}
GroupMemoryBarrierWithGroupSync();
if (maxZSample >= minZSample) {
InterlockedMin(sMinZ, asuint(minZSample));
InterlockedMax(sMaxZ, asuint(maxZSample));
}
GroupMemoryBarrierWithGroupSync();
float minTileZ = asfloat(sMinZ);
float maxTileZ = asfloat(sMaxZ);
// Work out scale/bias from [0, 1]
float2 tileScale = float2(FrameBufferCamNearFar.zw) * rcp(float(2 * GROUP_WIDTH));
float2 tileBias = tileScale - float2(GroupID.xy);
// Now work out composite projection matrix
// Relevant matrix columns for this tile frusta
float4 c1 = float4(Projection._11 * tileScale.x, 0.0f, tileBias.x, 0.0f);
float4 c2 = float4(0.0f, -Projection._22 * tileScale.y, tileBias.y, 0.0f);
float4 c4 = float4(0.0f, 0.0f, 1.0f, 0.0f);
// Derive frustum planes
float4 frustumPlanes[6];
// Sides
frustumPlanes[0] = c4 - c1;
frustumPlanes[1] = c4 + c1;
frustumPlanes[2] = c4 - c2;
frustumPlanes[3] = c4 + c2;
// Near/far
frustumPlanes[4] = float4(0.0f, 0.0f, 1.0f, -minTileZ);
frustumPlanes[5] = float4(0.0f, 0.0f, -1.0f, maxTileZ);
// Normalize frustum planes (near/far already normalized)
[unroll] for (uint i = 0; i < 4; ++i)
{
frustumPlanes[i] *= rcp(length(frustumPlanes[i].xyz));
}
// Cull lights for this tile
for (uint lightIndex = groupIndex; lightIndex < totalLights; lightIndex += (GROUP_WIDTH * GROUP_HEIGHT))
{
PointLight light = InputBuffer[lightIndex];
float3 lightVS = light.PosRad.xyz;// mul(float4(light.Pos.xyz, 1), View);
// Cull: point light sphere vs tile frustum
bool inFrustum = true;
[unroll]
for (uint i = 0; i < 6; ++i)
{
float d = dot(frustumPlanes[i], float4(lightVS, 1.0f));
inFrustum = inFrustum && (d >= -light.PosRad.w);
}
[branch]
if (inFrustum)
{
uint listIndex;
InterlockedAdd(sTileNumLights, 1, listIndex);
sTileLightIndices[listIndex] = lightIndex;
}
}
GroupMemoryBarrierWithGroupSync();
uint numLights = sTileNumLights;
if (all(globalCoords < FrameBufferCamNearFar.zw))
{
float4 NormalMap = NormalBuffer[globalCoords];
float3 normal = DecodeNormal(NormalMap);
if (numLights > 0)
{
float3 lit = float3(0.0f, 0.0f, 0.0f);
for (uint tileLightIndex = 0; tileLightIndex < numLights; ++tileLightIndex)
{
PointLight light = InputBuffer[sTileLightIndices[tileLightIndex]];
float3 lDir = light.PosRad.xyz - positionView;
lDir = normalize(lDir);
float3 nl = saturate(dot(lDir, normal));
lit += ((light.Color.xyz * light.Color.a) * nl) * 0.1f;
}
PointLightColor[globalCoords] = float4(lit, 1);
}
else
{
PointLightColor[globalCoords] = 0;
}
}
GroupMemoryBarrierWithGroupSync();
}
So I know the culling works because there are lights drawn, they just move with the camera.
Could it be a handedness issue?
Am I setting my CPU light code up right?
Have I messed my spaces up?
What am I missing?
Am I reconstructing my position from depth wrong? (don't think it's this because the culling works)
ps. I write depth out like this:
VS shader
float4 viewSpacePos = mul(float4(input.Position,1), WV);
output.Depth=viewSpacePos.z ;
PS Shader
-input.Depth.x / FarClip
I'm currently trying to get this bokeh shader to work with GPUImage: http://blenderartists.org/forum/showthread.php?237488-GLSL-depth-of-field-with-bokeh-v2-4-(update)
This is what I've got at the moment:
precision mediump float;
varying highp vec2 textureCoordinate;
varying highp vec2 textureCoordinate2;
uniform sampler2D inputImageTexture;
uniform sampler2D inputImageTexture2;
uniform float inputImageTextureWidth;
uniform float inputImageTextureHeight;
#define PI 3.14159265
float width = inputImageTextureWidth; //texture width
float height = inputImageTextureHeight; //texture height
vec2 texel = vec2(1.0/width,1.0/height);
//uniform variables from external script
uniform float focalDepth; //focal distance value in meters, but you may use autofocus option below
uniform float focalLength; //focal length in mm
uniform float fstop; //f-stop value
bool showFocus = false; //show debug focus point and focal range (red = focal point, green = focal range)
float znear = 0.1; //camera clipping start
float zfar = 5.0; //camera clipping end
//------------------------------------------
//user variables
int samples = 3; //samples on the first ring
int rings = 3; //ring count
bool manualdof = false; //manual dof calculation
float ndofstart = 1.0; //near dof blur start
float ndofdist = 2.0; //near dof blur falloff distance
float fdofstart = 1.0; //far dof blur start
float fdofdist = 3.0; //far dof blur falloff distance
float CoC = 0.03;//circle of confusion size in mm (35mm film = 0.03mm)
bool vignetting = false; //use optical lens vignetting?
float vignout = 1.3; //vignetting outer border
float vignin = 0.0; //vignetting inner border
float vignfade = 22.0; //f-stops till vignete fades
bool autofocus = false; //use autofocus in shader? disable if you use external focalDepth value
vec2 focus = vec2(0.5, 0.5); // autofocus point on screen (0.0,0.0 - left lower corner, 1.0,1.0 - upper right)
float maxblur = 1.0; //clamp value of max blur (0.0 = no blur,1.0 default)
float threshold = 0.5; //highlight threshold;
float gain = 2.0; //highlight gain;
float bias = 0.5; //bokeh edge bias
float fringe = 0.7; //bokeh chromatic aberration/fringing
bool noise = false; //use noise instead of pattern for sample dithering
float namount = 0.0001; //dither amount
bool depthblur = false; //blur the depth buffer?
float dbsize = 1.25; //depthblursize
/*
next part is experimental
not looking good with small sample and ring count
looks okay starting from samples = 4, rings = 4
*/
bool pentagon = false; //use pentagon as bokeh shape?
float feather = 0.4; //pentagon shape feather
//------------------------------------------
float penta(vec2 coords) //pentagonal shape
{
float scale = float(rings) - 1.3;
vec4 HS0 = vec4( 1.0, 0.0, 0.0, 1.0);
vec4 HS1 = vec4( 0.309016994, 0.951056516, 0.0, 1.0);
vec4 HS2 = vec4(-0.809016994, 0.587785252, 0.0, 1.0);
vec4 HS3 = vec4(-0.809016994,-0.587785252, 0.0, 1.0);
vec4 HS4 = vec4( 0.309016994,-0.951056516, 0.0, 1.0);
vec4 HS5 = vec4( 0.0 ,0.0 , 1.0, 1.0);
vec4 one = vec4( 1.0 );
vec4 P = vec4((coords),vec2(scale, scale));
vec4 dist = vec4(0.0);
float inorout = -4.0;
dist.x = dot( P, HS0 );
dist.y = dot( P, HS1 );
dist.z = dot( P, HS2 );
dist.w = dot( P, HS3 );
dist = smoothstep( -feather, feather, dist );
inorout += dot( dist, one );
dist.x = dot( P, HS4 );
dist.y = HS5.w - abs( P.z );
dist = smoothstep( -feather, feather, dist );
inorout += dist.x;
return clamp( inorout, 0.0, 1.0 );
}
float bdepth(vec2 coords) //blurring depth
{
float d = 0.0;
float kernel[9];
vec2 offset[9];
vec2 wh = vec2(texel.x, texel.y) * dbsize;
offset[0] = vec2(-wh.x,-wh.y);
offset[1] = vec2( 0.0, -wh.y);
offset[2] = vec2( wh.x -wh.y);
offset[3] = vec2(-wh.x, 0.0);
offset[4] = vec2( 0.0, 0.0);
offset[5] = vec2( wh.x, 0.0);
offset[6] = vec2(-wh.x, wh.y);
offset[7] = vec2( 0.0, wh.y);
offset[8] = vec2( wh.x, wh.y);
kernel[0] = 1.0/16.0; kernel[1] = 2.0/16.0; kernel[2] = 1.0/16.0;
kernel[3] = 2.0/16.0; kernel[4] = 4.0/16.0; kernel[5] = 2.0/16.0;
kernel[6] = 1.0/16.0; kernel[7] = 2.0/16.0; kernel[8] = 1.0/16.0;
for( int i=0; i<9; i++ )
{
float tmp = texture2D(inputImageTexture2, coords + offset[i]).r;
d += tmp * kernel[i];
}
return d;
}
vec3 color(vec2 coords,float blur) //processing the sample
{
vec3 col = vec3(0.0);
col.r = texture2D(inputImageTexture, coords + vec2(0.0,1.0)*texel*fringe*blur).r;
col.g = texture2D(inputImageTexture, coords + vec2(-0.866,-0.5)*texel*fringe*blur).g;
col.b = texture2D(inputImageTexture, coords + vec2(0.866,-0.5)*texel*fringe*blur).b;
vec3 lumcoeff = vec3(0.299,0.587,0.114);
float lum = dot(col.rgb, lumcoeff);
float thresh = max((lum-threshold)*gain, 0.0);
return col+mix(vec3(0.0),col,thresh*blur);
}
vec2 rand(vec2 coord) //generating noise/pattern texture for dithering
{
float noiseX = ((fract(1.0-coord.s*(width/2.0))*0.25)+(fract(coord.t*(height/2.0))*0.75))*2.0-1.0;
float noiseY = ((fract(1.0-coord.s*(width/2.0))*0.75)+(fract(coord.t*(height/2.0))*0.25))*2.0-1.0;
if (noise)
{
noiseX = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233))) * 43758.5453),0.0,1.0)*2.0-1.0;
noiseY = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233)*2.0)) * 43758.5453),0.0,1.0)*2.0-1.0;
}
return vec2(noiseX,noiseY);
}
vec3 debugFocus(vec3 col, float blur, float depth)
{
float edge = 0.002*depth; //distance based edge smoothing
float m = clamp(smoothstep(0.0,edge,blur),0.0,1.0);
float e = clamp(smoothstep(1.0-edge,1.0,blur),0.0,1.0);
col = mix(col,vec3(1.0,1.0,0.0),(1.0-m)*0.6);
col = mix(col,vec3(0.0,1.0,1.0),((1.0-e)-(1.0-m))*0.2);
return col;
}
float linearize(float depth)
{
return -zfar * znear / (depth * (zfar - znear) - zfar);
}
float vignette()
{
float dist = distance(textureCoordinate.xy, vec2(0.5,0.5));
dist = smoothstep(vignout+(fstop/vignfade), vignin+(fstop/vignfade), dist);
return clamp(dist,0.0,1.0);
}
void main()
{
//scene depth calculation
float depth = linearize(texture2D(inputImageTexture2, textureCoordinate2.xy).x);
if (depthblur)
{
depth = linearize(bdepth(textureCoordinate2.xy));
}
//focal plane calculation
float fDepth = focalDepth;
if (autofocus)
{
fDepth = linearize(texture2D(inputImageTexture2, focus).x);
}
//dof blur factor calculation
float blur = 0.0;
if (manualdof)
{
float a = depth-fDepth; //focal plane
float b = (a-fdofstart)/fdofdist; //far DoF
float c = (-a-ndofstart)/ndofdist; //near Dof
blur = (a>0.0)?b:c;
}
else
{
float f = focalLength; //focal length in mm
float d = fDepth*1000.0; //focal plane in mm
float o = depth*1000.0; //depth in mm
float a = (o*f)/(o-f);
float b = (d*f)/(d-f);
float c = (d-f)/(d*fstop*CoC);
blur = abs(a-b)*c;
}
blur = clamp(blur,0.0,1.0);
// calculation of pattern for ditering
vec2 noise = rand(textureCoordinate.xy)*namount*blur;
// getting blur x and y step factor
float w = (1.0/width)*blur*maxblur+noise.x;
float h = (1.0/height)*blur*maxblur+noise.y;
// calculation of final color
vec3 col = vec3(0.0);
if(blur < 0.05) //some optimization thingy
{
col = texture2D(inputImageTexture, textureCoordinate.xy).rgb;
}
else
{
col = texture2D(inputImageTexture, textureCoordinate.xy).rgb;
float s = 1.0;
int ringsamples;
for (int i = 1; i <= rings; i += 1)
{
ringsamples = i * samples;
for (int j = 0 ; j < ringsamples ; j += 1)
{
float step = PI*2.0 / float(ringsamples);
float pw = (cos(float(j)*step)*float(i));
float ph = (sin(float(j)*step)*float(i));
float p = 1.0;
if (pentagon)
{
p = penta(vec2(pw,ph));
}
col += color(textureCoordinate.xy + vec2(pw*w,ph*h),blur)*mix(1.0,(float(i))/(float(rings)),bias)*p;
s += 1.0*mix(1.0,(float(i))/(float(rings)),bias)*p;
}
}
col /= s; //divide by sample count
}
if (showFocus)
{
col = debugFocus(col, blur, depth);
}
if (vignetting)
{
col *= vignette();
}
gl_FragColor.rgb = col;
gl_FragColor.a = 1.0;
}
This is my bokeh filter, a subclass of GPUImageTwoInputFilter:
#implementation GPUImageBokehFilter
- (id)init;
{
NSString *fragmentShaderPathname = [[NSBundle mainBundle] pathForResource:#"BokehShader" ofType:#"fsh"];
NSString *fragmentShaderString = [NSString stringWithContentsOfFile:fragmentShaderPathname encoding:NSUTF8StringEncoding error:nil];
if (!(self = [super initWithFragmentShaderFromString:fragmentShaderString]))
{
return nil;
}
focalDepthUniform = [filterProgram uniformIndex:#"focalDepth"];
focalLengthUniform = [filterProgram uniformIndex:#"focalLength"];
fStopUniform = [filterProgram uniformIndex:#"fstop"];
[self setFocalDepth:1.0];
[self setFocalLength:35.0];
[self setFStop:2.2];
return self;
}
#pragma mark -
#pragma mark Accessors
- (void)setFocalDepth:(float)focalDepth {
_focalDepth = focalDepth;
[self setFloat:_focalDepth forUniform:focalDepthUniform program:filterProgram];
}
- (void)setFocalLength:(float)focalLength {
_focalLength = focalLength;
[self setFloat:_focalLength forUniform:focalLengthUniform program:filterProgram];
}
- (void)setFStop:(CGFloat)fStop {
_fStop = fStop;
[self setFloat:_fStop forUniform:fStopUniform program:filterProgram];
}
#end
And finally, this is how I use said filter:
#implementation ViewController {
GPUImageBokehFilter *bokehFilter;
GPUImagePicture *bokehMap;
UIImage *inputImage;
}
- (void)viewDidLoad
{
[super viewDidLoad];
inputImage = [UIImage imageNamed:#"stones"];
bokehMap = [[GPUImagePicture alloc] initWithImage:[UIImage imageNamed:#"bokehmask"]];
_backgroundImage.image = inputImage;
bokehFilter = [[GPUImageBokehFilter alloc] init];
[self processImage];
}
- (IBAction)dataInputUpdated:(id)sender {
[self processImage];
}
- (void *)processImage {
dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
GPUImagePicture *gpuPicture = [[GPUImagePicture alloc] initWithImage:inputImage];
[gpuPicture addTarget:bokehFilter];
[gpuPicture processImage];
[bokehMap addTarget:bokehFilter];
[bokehMap processImage];
[bokehFilter useNextFrameForImageCapture];
[bokehFilter setFloat:inputImage.size.width forUniformName:#"inputImageTextureWidth"];
[bokehFilter setFloat:inputImage.size.height forUniformName:#"inputImageTextureHeight"];
UIImage *blurredImage = [bokehFilter imageFromCurrentFramebuffer];
dispatch_async(dispatch_get_main_queue(), ^{
[self displayNewImage:blurredImage];
});
});
}
- (void)displayNewImage:(UIImage*)newImage {
[UIView transitionWithView:_backgroundImage
duration:.6f
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
_backgroundImage.image = newImage;
} completion:nil];
}
...
The first image is the one I'm trying to blur, the second one is a random gradient to test the shader's depth map thingy:
When I start the app on my iPhone, I get this:
After moving the slider (which triggers the dataInputChanged method), I get this:
While that admittedly looks much better than the first image, I still have some problems with this:
There's a diagonal noisy line (inside the red lines I put on the picture) that appears to be unblurred.
The top left of the image is blurry, even though it shouldn't be.
Why do I get this weird behavior? Shouldn't the shader output be the same every time?
Also, how do I get it to respect the depth map? My GLSL shader knowledge is very limited, so please be patient.
The diagonal artifact appears to be caused by your test gradient. You can see that it occurs at about the same place as where your gradient goes to completely white. Try spreading out the gradient so it only reaches 1.0 or 0.0 at the very corners of the image.
It's a pretty big question, and I can't make a full answer because I would really need to test the thing out.
But a few points: The final image that you put up is hard to work with. Because the image has been upscaled so much, I can't tell if it's actually blurred or if it just appears blurry because of the resolution. Regardless, the amount of blur that you're getting (when compared to the original link that you provided) suggests that something isn't working with the shader.
Another thing that concerns me is the //some optimization thingy comment that you've got in there. This is the sort of thing that's going to be responsible for an ugly line in your final output. Saying that you wont have any blur under blur < 0.05 isn't necessarily something that you can do! I would be expecting a nasty artifact as the shader transitions from the blur shader and into the 'optimized' part.
Hope that sheds some light, and good luck!
Have you tried enabling showFocus? This should show the focal point in red and the focal range in green which should help with debugging. You could also try enabling autofocus to ensure that the centre of the image is in focus, because at the moment it's not obvious which distance should be in focus, due to the linearize function changing coordinate systems. After that try tweaking fstop to get the desired amount of blur. You will probably also find that you will need greater than samples = 3 and rings = 3 to produce a smooth bokeh effect.
Your answers helped me get on the right track, and after a few hours of fiddling around with my code and the shader, I managed to get all bugs fixed. Here's what caused them and how I fixed them:
The ugly diagonal line was caused by the linearize() method, so I removed it and made the shader use the RGB values (or, to be more precise: only the R value) from the depth map without processing them first.
The blue-ish image I got from the shader was caused by my own incompetence. These two lines had to be put before the calls to processImage:
[bokehFilter setFloat:inputImage.size.width forUniformName:#"inputImageTextureWidth"];
[bokehFilter setFloat:inputImage.size.height forUniformName:#"inputImageTextureHeight"];
In hindsight, it's obvious why I only got results the second time I used the shader. After fixing those bugs, I went on to optimize it a bit to keep the execution time as low as possible, and now I can tell it to render 8 samples/4 rings and it does so in less than a second. Here's what that looks like:
Thanks for the answers, everyone, I probably wouldn't have gotten those bugs fixed without you.
i want to equalize two half face color images of the same subject and then merge them. Each of them has different values of hue saturation and brightness....using opencv how can i normalize/equalize each half image?
I tried performing cvEqualizeHist(v, v); on the v value of the converted HSV image, but two images still have significant difference and after the merge still has a line between the colors of the two halves...thanks
Have u tried to read this link? http://answers.opencv.org/question/75510/how-to-make-auto-adjustmentsbrightness-and-contrast-for-image-android-opencv-image-correction/
void Utils::BrightnessAndContrastAuto(const cv::Mat &src, cv::Mat &dst, float clipHistPercent)
{
CV_Assert(clipHistPercent >= 0);
CV_Assert((src.type() == CV_8UC1) || (src.type() == CV_8UC3) || (src.type() == CV_8UC4));
int histSize = 256;
float alpha, beta;
double minGray = 0, maxGray = 0;
//to calculate grayscale histogram
cv::Mat gray;
if (src.type() == CV_8UC1) gray = src;
else if (src.type() == CV_8UC3) cvtColor(src, gray, CV_BGR2GRAY);
else if (src.type() == CV_8UC4) cvtColor(src, gray, CV_BGRA2GRAY);
if (clipHistPercent == 0)
{
// keep full available range
cv::minMaxLoc(gray, &minGray, &maxGray);
}
else
{
cv::Mat hist; //the grayscale histogram
float range[] = { 0, 256 };
const float* histRange = { range };
bool uniform = true;
bool accumulate = false;
calcHist(&gray, 1, 0, cv::Mat(), hist, 1, &histSize, &histRange, uniform, accumulate);
// calculate cumulative distribution from the histogram
std::vector<float> accumulator(histSize);
accumulator[0] = hist.at<float>(0);
for (int i = 1; i < histSize; i++)
{
accumulator[i] = accumulator[i - 1] + hist.at<float>(i);
}
// locate points that cuts at required value
float max = accumulator.back();
clipHistPercent *= (max / 100.0); //make percent as absolute
clipHistPercent /= 2.0; // left and right wings
// locate left cut
minGray = 0;
while (accumulator[minGray] < clipHistPercent)
minGray++;
// locate right cut
maxGray = histSize - 1;
while (accumulator[maxGray] >= (max - clipHistPercent))
maxGray--;
}
// current range
float inputRange = maxGray - minGray;
alpha = (histSize - 1) / inputRange; // alpha expands current range to histsize range
beta = -minGray * alpha; // beta shifts current range so that minGray will go to 0
// Apply brightness and contrast normalization
// convertTo operates with saurate_cast
src.convertTo(dst, -1, alpha, beta);
// restore alpha channel from source
if (dst.type() == CV_8UC4)
{
int from_to[] = { 3, 3 };
cv::mixChannels(&src, 4, &dst, 1, from_to, 1);
}
return;
}
I'm not sure as I'm now facing the same problem,
but maybe try to equalize the H & S values instead of the V?
Also try manually adjusting it using Photoshop to see what works best and then try to replicate it using code.