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Added alpha blurring and image scale preservation #11

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529a92c
Added options to preserve image scale when recreating the UIImage fro…
agentk Mar 28, 2013
271bee0
Added alpha layer bluring in addition to the RGB
agentk Mar 28, 2013
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205 changes: 116 additions & 89 deletions Classes/UIImage+StackBlur.m
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Original file line number Diff line number Diff line change
Expand Up @@ -10,13 +10,13 @@
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
Expand All @@ -30,7 +30,7 @@
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of the FreeBSD Project.
*/

Expand All @@ -48,7 +48,7 @@ @implementation UIImage (StackBlur)
// by Mario Klingemann

- (UIImage*) stackBlur:(NSUInteger)inradius
{
{
if (inradius < 1){
return self;
}
Expand All @@ -65,35 +65,35 @@ - (UIImage*) stackBlur:(NSUInteger)inradius
UIImage *tmpImage = [self normalize];
inImage = tmpImage.CGImage;
}
CFMutableDataRef m_DataRef = CFDataCreateMutableCopy(0, 0, CGDataProviderCopyData(CGImageGetDataProvider(inImage)));
CFMutableDataRef m_DataRef = CFDataCreateMutableCopy(0, 0, CGDataProviderCopyData(CGImageGetDataProvider(inImage)));
UInt8 * m_PixelBuf=malloc(CFDataGetLength(m_DataRef));
CFDataGetBytes(m_DataRef,
CFRangeMake(0,CFDataGetLength(m_DataRef)) ,
m_PixelBuf);
CGContextRef ctx = CGBitmapContextCreate(m_PixelBuf,
CGImageGetWidth(inImage),
CGImageGetHeight(inImage),

CGContextRef ctx = CGBitmapContextCreate(m_PixelBuf,
CGImageGetWidth(inImage),
CGImageGetHeight(inImage),
CGImageGetBitsPerComponent(inImage),
CGImageGetBytesPerRow(inImage),
CGImageGetColorSpace(inImage),
CGImageGetBitmapInfo(inImage)
CGImageGetBytesPerRow(inImage),
CGImageGetColorSpace(inImage),
CGImageGetBitmapInfo(inImage)
);

// Apply stack blur
const int imageWidth = CGImageGetWidth(inImage);
const int imageHeight = CGImageGetHeight(inImage);
[self.class applyStackBlurToBuffer:m_PixelBuf
width:imageWidth
height:imageHeight
withRadius:inradius];

// Make new image
CGImageRef imageRef = CGBitmapContextCreateImage(ctx);
CGContextRelease(ctx);
UIImage *finalImage = [UIImage imageWithCGImage:imageRef];
CGImageRelease(imageRef);
CGContextRelease(ctx);

UIImage *finalImage = [UIImage imageWithCGImage:imageRef scale:self.scale orientation:self.imageOrientation];
CGImageRelease(imageRef);
CFRelease(m_DataRef);
free(m_PixelBuf);
return finalImage;
Expand All @@ -105,202 +105,229 @@ + (void) applyStackBlurToBuffer:(UInt8*)targetBuffer width:(const int)w height:(
const int radius = inradius; // Transform unsigned into signed for further operations
const int wm = w - 1;
const int hm = h - 1;
const int wh = w*h;
const int wh = w * h;
const int div = radius + radius + 1;
const int r1 = radius + 1;
const int divsum = SQUARE((div+1)>>1);
const int divsum = SQUARE((div+1) >> 1);

// Small buffers
int stack[div*3];
zeroClearInt(stack, div*3);
int stack[div * 4];
zeroClearInt(stack, div * 4);

int vmin[MAX(w,h)];
zeroClearInt(vmin, MAX(w,h));
int vmin[MAX(w, h)];
zeroClearInt(vmin, MAX(w, h));

// Large buffers
int *r = malloc(wh*sizeof(int));
int *g = malloc(wh*sizeof(int));
int *b = malloc(wh*sizeof(int));
int *r = malloc(wh * sizeof(int));
int *g = malloc(wh * sizeof(int));
int *b = malloc(wh * sizeof(int));
int *a = malloc(wh * sizeof(int));
zeroClearInt(r, wh);
zeroClearInt(g, wh);
zeroClearInt(b, wh);
zeroClearInt(a, wh);

const size_t dvcount = 256 * divsum;
int *dv = malloc(sizeof(int) * dvcount);
for (int i = 0;i < dvcount;i++) {
for (int i = 0; i < dvcount; i++) {
dv[i] = (i / divsum);
}

// Variables
int x, y;
int *sir;
int routsum,goutsum,boutsum;
int rinsum,ginsum,binsum;
int rsum, gsum, bsum, p, yp;
int routsum, goutsum, boutsum, aoutsum;
int rinsum, ginsum, binsum, ainsum;
int rsum, gsum, bsum, asum, p, yp;
int stackpointer;
int stackstart;
int rbs;

int yw = 0, yi = 0;
for (y = 0;y < h;y++) {
rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
for(int i = -radius;i <= radius;i++){
sir = &stack[(i + radius)*3];
int offset = (yi + MIN(wm, MAX(i, 0)))*4;
for (y = 0; y < h; y++) {
rinsum = ginsum = binsum = ainsum = routsum = goutsum = boutsum = aoutsum = rsum = gsum = bsum = asum = 0;

for(int i = -radius; i <= radius; i++){
sir = &stack[(i + radius) * 4];
int offset = (yi + MIN(wm, MAX(i, 0))) * 4;
sir[0] = targetBuffer[offset];
sir[1] = targetBuffer[offset + 1];
sir[2] = targetBuffer[offset + 2];

sir[3] = targetBuffer[offset + 3];

rbs = r1 - abs(i);
rsum += sir[0] * rbs;
gsum += sir[1] * rbs;
bsum += sir[2] * rbs;
asum += sir[3] * rbs;
if (i > 0){
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];
ainsum += sir[3];
} else {
routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];
aoutsum += sir[3];
}
}
stackpointer = radius;
for (x = 0;x < w;x++) {

for (x = 0; x < w; x++) {
r[yi] = dv[rsum];
g[yi] = dv[gsum];
b[yi] = dv[bsum];

a[yi] = dv[asum];

rsum -= routsum;
gsum -= goutsum;
bsum -= boutsum;

asum -= aoutsum;

stackstart = stackpointer - radius + div;
sir = &stack[(stackstart % div)*3];
sir = &stack[(stackstart % div) * 4];

routsum -= sir[0];
goutsum -= sir[1];
boutsum -= sir[2];

aoutsum -= sir[3];

if (y == 0){
vmin[x] = MIN(x + radius + 1, wm);
}
int offset = (yw + vmin[x])*4;

int offset = (yw + vmin[x]) * 4;
sir[0] = targetBuffer[offset];
sir[1] = targetBuffer[offset + 1];
sir[2] = targetBuffer[offset + 2];
sir[3] = targetBuffer[offset + 3];
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];

ainsum += sir[3];

rsum += rinsum;
gsum += ginsum;
bsum += binsum;

asum += ainsum;

stackpointer = (stackpointer + 1) % div;
sir = &stack[(stackpointer % div)*3];
sir = &stack[(stackpointer % div) * 4];

routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];

aoutsum += sir[3];

rinsum -= sir[0];
ginsum -= sir[1];
binsum -= sir[2];

ainsum -= sir[3];

yi++;
}
yw += w;
}
for (x = 0;x < w;x++) {
rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
yp = -radius*w;
for(int i = -radius;i <= radius;i++) {

for (x = 0; x < w; x++) {
rinsum = ginsum = binsum = ainsum = routsum = goutsum = boutsum = aoutsum = rsum = gsum = bsum = asum = 0;
yp = -radius * w;
for(int i = -radius; i <= radius; i++) {
yi = MAX(0, yp) + x;
sir = &stack[(i + radius)*3];

sir = &stack[(i + radius) * 4];

sir[0] = r[yi];
sir[1] = g[yi];
sir[2] = b[yi];

sir[3] = a[yi];

rbs = r1 - abs(i);

rsum += r[yi]*rbs;
gsum += g[yi]*rbs;
bsum += b[yi]*rbs;


rsum += r[yi] * rbs;
gsum += g[yi] * rbs;
bsum += b[yi] * rbs;
asum += a[yi] * rbs;

if (i > 0) {
rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];
ainsum += sir[3];
} else {
routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];
aoutsum += sir[3];
}

if (i < hm) {
yp += w;
}
}
yi = x;
stackpointer = radius;
for (y = 0;y < h;y++) {
int offset = yi*4;
for (y = 0; y < h; y++) {
int offset = yi * 4;
targetBuffer[offset] = dv[rsum];
targetBuffer[offset + 1] = dv[gsum];
targetBuffer[offset + 2] = dv[bsum];
targetBuffer[offset + 3] = dv[asum];
rsum -= routsum;
gsum -= goutsum;
bsum -= boutsum;

asum -= aoutsum;

stackstart = stackpointer - radius + div;
sir = &stack[(stackstart % div)*3];
sir = &stack[(stackstart % div) * 4];

routsum -= sir[0];
goutsum -= sir[1];
boutsum -= sir[2];

if (x == 0){
vmin[y] = MIN(y + r1, hm)*w;
aoutsum -= sir[3];

if (x == 0) {
vmin[y] = MIN(y + r1, hm) * w;
}
p = x + vmin[y];

sir[0] = r[p];
sir[1] = g[p];
sir[2] = b[p];

sir[3] = a[p];

rinsum += sir[0];
ginsum += sir[1];
binsum += sir[2];

ainsum += sir[3];

rsum += rinsum;
gsum += ginsum;
bsum += binsum;

asum += ainsum;

stackpointer = (stackpointer + 1) % div;
sir = &stack[stackpointer*3];
sir = &stack[stackpointer * 4];

routsum += sir[0];
goutsum += sir[1];
boutsum += sir[2];

aoutsum += sir[3];

rinsum -= sir[0];
ginsum -= sir[1];
binsum -= sir[2];

ainsum -= sir[3];

yi += w;
}
}

free(r);
free(g);
free(b);
free(a);
free(dv);
}

Expand All @@ -321,9 +348,9 @@ - (UIImage *) normalize {
CGContextDrawImage(thumbBitmapCtxt, destRect, self.CGImage);
CGImageRef tmpThumbImage = CGBitmapContextCreateImage(thumbBitmapCtxt);
CGContextRelease(thumbBitmapCtxt);
UIImage *result = [UIImage imageWithCGImage:tmpThumbImage];
UIImage *result = [UIImage imageWithCGImage:tmpThumbImage scale:self.scale orientation:self.imageOrientation];
CGImageRelease(tmpThumbImage);

return result;
}

Expand Down