I am working on one photographic app in that I am adding 10 effects to one image. I am using some libraries for this. After sometime app is crashing . Its showing memory warning. I am using image after compression but still also app is crashing . Can any one tell me how to solve this memory warning . I am using this following code for image compression
-(UIImage *)resizeImage:(UIImage *)image {
int w = image.size.width;
int h = image.size.height;
CGImageRef imageRef = [image CGImage];
int width, height;
int destWidth = 640;
int destHeight = 480;
if(w > h){
width = destWidth;
height = h*destWidth/w;
} else {
height = destHeight;
width = w*destHeight/h;
}
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmap;
bitmap = CGBitmapContextCreate(NULL, width, height, 8, 4 * width, colorSpace, kCGImageAlphaPremultipliedFirst);
if (image.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM (bitmap, M_PI/2);
CGContextTranslateCTM (bitmap, 0, -height);
} else if (image.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (bitmap, -M_PI/2);
CGContextTranslateCTM (bitmap, -width, 0);
} else if (image.imageOrientation == UIImageOrientationUp) {
} else if (image.imageOrientation == UIImageOrientationDown) {
CGContextTranslateCTM (bitmap, width,height);
CGContextRotateCTM (bitmap, -M_PI);
}
CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage *result = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap);
CGImageRelease(ref);
return result;
}
and I am using that GPUImage library and I have added GPUImageView for displaying image.
Please help me if someone has any idea.
Thanks in advance.
You need to release colorspace:
CGColorSpaceRelease(colorspace);
This may be a reason of leak, but if you call resizeImage many times then it can be the reason of crashes
Related
I used crop function that crop image . It is work good when i take photo from photo library but when i use camera to take picture and crop the image. the crop function give me a wrong crop image .
My crop logic:
float zoomScale = 1.0 / [scrollView zoomScale];
CGRect rect;
rect.origin.x = [scrollView contentOffset].x * zoomScale;
rect.origin.y = [scrollView contentOffset].y * zoomScale;
rect.size.width = [scrollView bounds].size.width * zoomScale;
rect.size.height = [scrollView bounds].size.height * zoomScale;
UIImage *cropped = [self cropImage:imageView.image toRect:rect];//[UIImage imageWithCGImage:cr];
//CGImageRelease(cr);
return cropped;
static inline double radians (double degrees) {return degrees * M_PI/180;}
-(UIImage*)cropImage:(UIImage*)originalImage toRect:(CGRect)rect{
CGImageRef imageRef = CGImageCreateWithImageInRect([originalImage CGImage], rect);
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
CGContextRef bitmap = CGBitmapContextCreate(NULL, rect.size.width, rect.size.height, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
if (originalImage.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -rect.size.height);
} else if (originalImage.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (bitmap, radians(-90));
CGContextTranslateCTM (bitmap, -rect.size.width, 0);
} else if (originalImage.imageOrientation == UIImageOrientationUp) {
// NOTHING
} else if (originalImage.imageOrientation == UIImageOrientationDown) {
CGContextTranslateCTM (bitmap, rect.size.width, rect.size.height);
CGContextRotateCTM (bitmap, radians(-180.));
}
CGContextDrawImage(bitmap, CGRectMake(0, 0, rect.size.width, rect.size.height), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage *resultImage=[UIImage imageWithCGImage:ref];
CGImageRelease(imageRef);
CGContextRelease(bitmap);
CGImageRelease(ref);
return resultImage;
}
what is the problem with my code ?
image taken from camera is not proper crop .
Please solve it .
I want whole bottle image see in first image that i have to set but when i press crop button and give me a wrong image . seein second image.
How do I resize the UIImageView in a UITableViewCell? I'm passing in a large image (at least 100x100px), so the image itself shouldn't be the problem (it should scale down with the imageview)
cell.imageView.image = [UIImage imageNamed:#"unread.png"];
CGSize itemSize = CGSizeMake(25, 25);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[cell.imageView.image drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
Normally the UIImageView in the UITableViewCell is 43 points (or 86 pixels) in height and width. I'd like to size it down to 20 x 20 but this isn't doing anything. Am I missing something?
You can't change the frame of uiimageview of uitableviewcell. You can choose an option from the below
Create a custom cell and place a uiimageview at your requirement(which is the best solution and i prefer this one).
Use core graphics inside your cellForRowAtIndexPath:
CGSize itemSize = CGSizeMake(width, height);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[cell.imageView.image drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
I hope following function useful for you:
+(UIImage*)resizeImage:(UIImage *)image width:(int)width height:(int)height {
CGFloat targetWidth = width;
CGFloat targetHeight = height;
CGImageRef imageRef = [image CGImage];
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
if (bitmapInfo == kCGImageAlphaNone) {
bitmapInfo = kCGImageAlphaNoneSkipLast;
}
CGContextRef bitmap;
if (image.imageOrientation == UIImageOrientationUp || image.imageOrientation == UIImageOrientationDown) {
bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
} else {
bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
}
// In the right or left cases, we need to switch scaledWidth and scaledHeight,
// and also the thumbnail point
if (image.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -targetHeight);
} else if (image.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (bitmap, radians(-90));
CGContextTranslateCTM (bitmap, -targetWidth, 0);
} else if (image.imageOrientation == UIImageOrientationUp) {
// NOTHING
} else if (image.imageOrientation == UIImageOrientationDown) {
CGContextTranslateCTM (bitmap, targetWidth, targetHeight);
CGContextRotateCTM (bitmap, radians(-180.));
}
CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage* newImage = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap);
CGImageRelease(ref);
return newImage;
}
This question already has answers here:
Rotating a CGImage
(6 answers)
Closed 8 years ago.
I have a UIImage that appears to be oriented the correct way when my iPad is held in portrait, but when I get the CGImageRef associated with it, the CGImageRef is rotated 90 degrees counterclockwise. After some Googling, I've learned that this is because the CGImageRef has no orientation data unlike the UIImage. I need to view and modify some of the pixels in the CGImageRef, and I'm currently doing this by directly accessing the rawData variable (image is a UIImage*):
CGImageRef imageRef = [image CGImage];
CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB(); //maybe make ...Gray();
unsigned char *rawData = (unsigned char*) calloc(height * width * 4, sizeof(unsigned char));
CGContextRef context = CGBitmapContextCreate(rawData, width, height, bitsPerComponent, bytesPerRow, colorSpaceRef, kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);
CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
However, in order for me to properly modify the pixel data stored in rawData, I need the CGImageRef to be in the correct orientation. How can I rotate the CGImageRef 90 degrees clockwise and then access rawData (the pixel information)?
try this :
CGImageRef imageRef = [sourceImage CGImage];
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
CGContextRef bitmap;
if (sourceImage.imageOrientation == UIImageOrientationUp || sourceImage.imageOrientation == UIImageOrientationDown) {
bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
} else {
bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
}
if (sourceImage.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -targetHeight);
} else if (sourceImage.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (bitmap, radians(-90));
CGContextTranslateCTM (bitmap, -targetWidth, 0);
} else if (sourceImage.imageOrientation == UIImageOrientationUp) {
// NOTHING
} else if (sourceImage.imageOrientation == UIImageOrientationDown) {
CGContextTranslateCTM (bitmap, targetWidth, targetHeight);
CGContextRotateCTM (bitmap, radians(-180.));
}
CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
I would like to implement an OCR application that would recognize text from Photos.
I succeeded in Compiling and Integration the Tesseract Engine in iOS, I succeeded in getting reasonable detection when photographing clear documents (or a photoshot of this text from the screen) but for other text such as signposts, shop signs, colour background, the detection failed.
The Question is What kind of image processing preparations are necessary to get better recognition. For example, I expect that we need to transform the images into grayscale /B&W as well as fixing contrast etc.
How can this be done in iOS, Is there a package for this?
I'm currently working on the same thing.
I found that a PNG saved in photoshop worked fine, but an image which was originally sourced from the camera then imported into the app never worked.
Don't ask me to explain it - but applying this function made these images work. Maybe it'll work for you too.
// this does the trick to have tesseract accept the UIImage.
UIImage * gs_convert_image (UIImage * src_img) {
CGColorSpaceRef d_colorSpace = CGColorSpaceCreateDeviceRGB();
/*
* Note we specify 4 bytes per pixel here even though we ignore the
* alpha value; you can't specify 3 bytes per-pixel.
*/
size_t d_bytesPerRow = src_img.size.width * 4;
unsigned char * imgData = (unsigned char*)malloc(src_img.size.height*d_bytesPerRow);
CGContextRef context = CGBitmapContextCreate(imgData, src_img.size.width,
src_img.size.height,
8, d_bytesPerRow,
d_colorSpace,
kCGImageAlphaNoneSkipFirst);
UIGraphicsPushContext(context);
// These next two lines 'flip' the drawing so it doesn't appear upside-down.
CGContextTranslateCTM(context, 0.0, src_img.size.height);
CGContextScaleCTM(context, 1.0, -1.0);
// Use UIImage's drawInRect: instead of the CGContextDrawImage function, otherwise you'll have issues when the source image is in portrait orientation.
[src_img drawInRect:CGRectMake(0.0, 0.0, src_img.size.width, src_img.size.height)];
UIGraphicsPopContext();
/*
* At this point, we have the raw ARGB pixel data in the imgData buffer, so
* we can perform whatever image processing here.
*/
// After we've processed the raw data, turn it back into a UIImage instance.
CGImageRef new_img = CGBitmapContextCreateImage(context);
UIImage * convertedImage = [[UIImage alloc] initWithCGImage:
new_img];
CGImageRelease(new_img);
CGContextRelease(context);
CGColorSpaceRelease(d_colorSpace);
free(imgData);
return convertedImage;
}
I've also gone a lot of experimentation preparing the image for tesseract. Resizing, converting to grayscale, then adjusting brightness and contrast seems to work best.
I've also tried this GPUImage library. https://github.com/BradLarson/GPUImage
And the GPUImageAverageLuminanceThresholdFilter seems to give me a great adjusted image, but tesseract doesn't seem to work well with it.
I've also put in opencv into my project and plan to try out it's image routines. Possibly even some box detection to find the text area (i'm hoping this will speed up tesseract).
I have used the code above but added two other function calls as well to convert the image so that it will work with the Tesseract.
Firstly I used an image resize script to convert to 640 x 640 which seems to be more manageable for the Tesseract.
-(UIImage *)resizeImage:(UIImage *)image {
CGImageRef imageRef = [image CGImage];
CGImageAlphaInfo alphaInfo = CGImageGetAlphaInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGColorSpaceCreateDeviceRGB();
if (alphaInfo == kCGImageAlphaNone)
alphaInfo = kCGImageAlphaNoneSkipLast;
int width, height;
width = 640;//[image size].width;
height = 640;//[image size].height;
CGContextRef bitmap;
if (image.imageOrientation == UIImageOrientationUp | image.imageOrientation == UIImageOrientationDown) {
bitmap = CGBitmapContextCreate(NULL, width, height, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, alphaInfo);
} else {
bitmap = CGBitmapContextCreate(NULL, height, width, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, alphaInfo);
}
if (image.imageOrientation == UIImageOrientationLeft) {
NSLog(#"image orientation left");
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -height);
} else if (image.imageOrientation == UIImageOrientationRight) {
NSLog(#"image orientation right");
CGContextRotateCTM (bitmap, radians(-90));
CGContextTranslateCTM (bitmap, -width, 0);
} else if (image.imageOrientation == UIImageOrientationUp) {
NSLog(#"image orientation up");
} else if (image.imageOrientation == UIImageOrientationDown) {
NSLog(#"image orientation down");
CGContextTranslateCTM (bitmap, width,height);
CGContextRotateCTM (bitmap, radians(-180.));
}
CGContextDrawImage(bitmap, CGRectMake(0, 0, width, height), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage *result = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap);
CGImageRelease(ref);
return result;
}
So that the radians work ensure you declare it above the #implementation
static inline double radians (double degrees) {return degrees * M_PI/180;}
Then I convert to grayscale.
I found this article Convert image to grayscale on converting to grayscale.
I have used the code from here successfully and can now read different colour text and different colour backgrounds
I have modified the code slightly to work as a function within a class rather than as its own class which the other person did
- (UIImage *) toGrayscale:(UIImage*)img
{
const int RED = 1;
const int GREEN = 2;
const int BLUE = 3;
// Create image rectangle with current image width/height
CGRect imageRect = CGRectMake(0, 0, img.size.width * img.scale, img.size.height * img.scale);
int width = imageRect.size.width;
int height = imageRect.size.height;
// the pixels will be painted to this array
uint32_t *pixels = (uint32_t *) malloc(width * height * sizeof(uint32_t));
// clear the pixels so any transparency is preserved
memset(pixels, 0, width * height * sizeof(uint32_t));
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
// create a context with RGBA pixels
CGContextRef context = CGBitmapContextCreate(pixels, width, height, 8, width * sizeof(uint32_t), colorSpace,
kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedLast);
// paint the bitmap to our context which will fill in the pixels array
CGContextDrawImage(context, CGRectMake(0, 0, width, height), [img CGImage]);
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
uint8_t *rgbaPixel = (uint8_t *) &pixels[y * width + x];
// convert to grayscale using recommended method: http://en.wikipedia.org/wiki/Grayscale#Converting_color_to_grayscale
uint32_t gray = 0.3 * rgbaPixel[RED] + 0.59 * rgbaPixel[GREEN] + 0.11 * rgbaPixel[BLUE];
// set the pixels to gray
rgbaPixel[RED] = gray;
rgbaPixel[GREEN] = gray;
rgbaPixel[BLUE] = gray;
}
}
// create a new CGImageRef from our context with the modified pixels
CGImageRef image = CGBitmapContextCreateImage(context);
// we're done with the context, color space, and pixels
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
free(pixels);
// make a new UIImage to return
UIImage *resultUIImage = [UIImage imageWithCGImage:image
scale:img.scale
orientation:UIImageOrientationUp];
// we're done with image now too
CGImageRelease(image);
return resultUIImage;
}
I have a closed path defined as a CGPath (actually, CGMutablePath).
I want to color burn a specific region of a UIImage defined by the path. I've been fiddling around with Core Graphics, but currently my only options are to color tint a rectangular area defined by a CGRect, not a path.
Can anyone point me in the right direction?
--Update
Using the help of Rob I managed to rotate the image I got from the camera 90 deg to let it appear correctly in the UIImageview..
Only problem I have left is the PATH i need to draw is still 90 degrees of, and out of scale. The code i currently use is as following:
- (UIImage*)applyColorFillWithPath:(CGMutablePathRef) path withColor:(UIColor*)color {
CGFloat targetWidth = self.size.width;
CGFloat targetHeight = self.size.height;
CGImageRef imageRef = [self CGImage];
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
if (bitmapInfo == kCGImageAlphaNone) {
bitmapInfo = kCGImageAlphaNoneSkipLast;
}
CGContextRef context;
if (self.imageOrientation == UIImageOrientationUp || self.imageOrientation == UIImageOrientationDown) {
//UIGraphicsBeginImageContext(CGSizeMake(targetWidth, targetHeight));
context = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
} else {
//UIGraphicsBeginImageContext(CGSizeMake(targetHeight, targetWidth));
context = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
}
// set the fill color
//[color setFill];
if (self.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM(context, radians(90));
CGContextTranslateCTM (context, 0, -targetHeight);
} else if (self.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (context, radians(-90));
CGContextTranslateCTM (context, -targetWidth, 0);
} else if (self.imageOrientation == UIImageOrientationUp) {
// NOTHING
} else if (self.imageOrientation == UIImageOrientationDown) {
CGContextTranslateCTM (context, targetWidth, targetHeight);
CGContextRotateCTM (context, radians(-180));
}
CGContextDrawImage(context, CGRectMake(0, 0, targetWidth, targetHeight),imageRef);
CGContextBeginPath(context);
CGContextAddPath(context, path);
CGContextSaveGState(context);
CGContextClip(context);
CGContextSetBlendMode(context, kCGBlendModeNormal);
CGContextSetFillColorWithColor(context, color.CGColor);
CGContextFillRect(context, CGPathGetBoundingBox(path));
CGContextRestoreGState(context);
// Turn the bitmap context into a UIImage.
CGImageRef cgImage = CGBitmapContextCreateImage(context);
CGContextRelease(context);
UIImage *coloredImg = [UIImage imageWithCGImage:cgImage scale:1 orientation:UIImageOrientationUp];
CGImageRelease(cgImage);
//return the color-burned image
return coloredImg;
}
The following image is the result. De red rectangle is a representation of the CGPATH. The white square is actually the result of the above method on the path.
http://i41.tinypic.com/f1zbdi.png
I suppose I need to manually rotate the CGPATH 90 degrees using COS math's and what not.. Although I might oversee something.. ?
Set the context's clipping path to your path to constrain the affected pixels.
CGContextRef gc = myGraphicsContext();
CGMutablePathRef path = myMutablePathRef();
CGContextBeginPath(gc);
CGContextAddPath(gc, path);
CGContextSaveGState(gc); {
CGContextClip(gc);
// Do color burn. For example:
CGContextSetBlendMode(gc, kCGBlendModeColorBurn);
CGContextSetFillColorWithColor(gc, [UIColor redColor].CGColor);
CGContextFillRect(gc, CGPathGetBoundingBox(path));
} CGContextRestoreGState(gc);