How to send IplImage from server to iPod client UIImage via TCP
I have a server in linux using the Berkeley_sockets and I create a TCP connection with an iPod client. I have an IplImage* img;
to send from the server to the iPod. I use the write(socket,/*DATA*/,43200);
command and the data i tried to send is: reinterpret_cast<char*>(img)
, img
and img->imageData
. All of this choices actually send any kind of data.
On the iPod side I receive data this way (as i've seen here in SO. Don't mind the complicated stuff, it's just for receiving all the data from a single image.):
bytesRead = [iStream read: (char*)[buffer mutableBytes] + totalBytesRead maxLength: 43200 - totalBytesRead];
After receiving the whole image, i have this:
[buffer setLength: 43200];
NSData *imagem = [NSData dataWithBytes:buffer length:43200];
UIImage *final= [self UIImageFromIplImage:imagem];
Now.. i know i could have openCV working on the iPod, but i can't find a simple explanation on how to get it to work, so I used the second code from this webpage and adapted it, since i know all the specifications of my image (for instance I set up all the variables from the CGImageCreate()
function.):
- (UIImage *)UIImageFromIplImage:(NSData *)image {
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
// Allocating the buffer for CGImage
NSData *data = [NSData dataWithBytes:image length:43200];
CGDataProviderRef provider = CGDataProviderCreateWithCFData((CFDataRef开发者_如何学C)data);
// Creating CGImage from chunk of IplImage
size_t width = 240;
size_t height = 180;
size_t depth = 8; //bitsPerComponent
size_t depthXnChannels = 8; //bitsPerPixel
size_t widthStep = 240; //bytesPerRow
CGImageRef imageRef = CGImageCreate(width, height, depth, depthXnChannels, widthStep, colorSpace, kCGImageAlphaNone|kCGBitmapByteOrderDefault,provider, NULL, false, kCGRenderingIntentDefault);
// Getting UIImage from CGImage
UIImage *ret = [UIImage imageWithCGImage:imageRef];
lolView.image = ret;
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return ret;
}
THE PROBLEM: When I display the image, I get it completely weird and ´random´, even though the image sent is always the same. I really have no idea what's wrong..
PS: The TCP connection is working fine with other data, like numbers or words. And the image is grayscale.
Thanks for all the help.
I got it working like this. On the server side (code::blocks in linux with openframeworks (& ofxOpenCv)):
img.allocate(240, 180, OF_IMAGE_COLOR); //ofImage
img2.allocate(240, 180); //ofxCvColorImage
frame = cvCreateImage(cvSize(240,180), IPL_DEPTH_8U, 3); //IplImage
bw = cvCreateImage(cvSize(240,180), IPL_DEPTH_8U, 1); //IplImage
gray.allocate(240, 180); //ofxCvGrayscaleImage
///ofImage
img.loadImage("lol.jpg");
///ofImage -> ofxCvColor
img2.setFromPixels(img.getPixels(), 240, 180);
///ofxCvColor -> IplImage
frame = img2.getCvImage();
///IplImage in GRAY
cvCvtColor(frame,bw,CV_RGB2GRAY);
cvThreshold(bw,bw,200,255,CV_THRESH_BINARY); //It is actually a binary image
gray = bw;
pix = gray.getPixels();
n=write(newsockfd,pix,43200);
On the client side (iPod 4.3):
-(UIImage *) dataFromIplImageToUIImage:(unsigned char *) rawData;
{
size_t width = 240;
size_t height = 180;
size_t depth = 8; //bitsPerComponent
size_t depthXnChannels = 8; //bitsPerPixel
size_t widthStep = 240; //bytesPerRow
CGContextRef ctx = CGBitmapContextCreate(rawData, width, height, depth, widthStep, CGColorSpaceCreateDeviceGray(), kCGImageAlphaNone);
CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
UIImage* rawImage = [UIImage imageWithCGImage:imageRef];
CGContextRelease(ctx);
myImageView.image = rawImage;
return rawImage;
free(rawData);
}
Probably there's an easier way to do this, but hey, gets the work done. Hope this helps anyone.
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