Convert raw image data to jpeg in swift - swift

Question

I am trying to convert the raw image data to jpeg in swift. But unfortunately, the jpeg image created is skewed. Please find below the code used for the conversion.
let rawPtr = (rawImgData as NSData).bytes
let mutableRawPtr = UnsafeMutableRawPointer.init(mutating: rawPtr)
let context = CGContext.init(data: mutableRawPtr,
width: 750,
height: 1334,
bitsPerComponent: 32,
bytesPerRow: (8 * 750)/8,
space: CGColorSpaceCreateDeviceRGB(),
bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue())
let imageRef = CGContext.makeImage(context!)
let imageRep = NSBitmapImageRep(cgImage: imageRef()!)
let finalData = imageRep.representation(using: .jpeg,
properties: [NSBitmapImageRep.PropertyKey.compressionFactor : 0.5])
Here's the converted jpeg image
Any help or pointers would be greatly appreciated. Thanks in advance!

Answer 1

Finally figured out the answer
var width:size_t?
var height:size_t?
let bitsPerComponent:size_t = 8
var bytesPerRow:size_t?
var bitmapInfo: UInt32
if #available(OSX 10.12, *) {
bitmapInfo = UInt32(CGImageAlphaInfo.premultipliedFirst.rawValue) | UInt32(CGImageByteOrderInfo.order32Little.rawValue)
} else {
bitmapInfo = UInt32(CGImageAlphaInfo.premultipliedFirst.rawValue)
}
let colorSpace = CGColorSpaceCreateDeviceRGB()
do {
let streamAttributesFuture = self.bitmapStream?.streamAttributes()
streamAttributesFuture?.onQueue(.main, notifyOfCompletion: { (streamAttributesFut) in
})
try streamAttributesFuture?.await()
let dict = streamAttributesFuture?.result
width = (dict?.attributes["width"] as! Int)
height = (dict?.attributes["height"] as! Int)
bytesPerRow = (dict?.attributes["row_size"] as! Int)
} catch let frameError{
print("frame error = \(frameError)")
return
}
let rawPtr = (data as NSData).bytes
let mutableRawPtr = UnsafeMutableRawPointer.init(mutating: rawPtr)
let context = CGContext.init(data: mutableRawPtr, width: width!, height: height!, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow!, space: colorSpace, bitmapInfo: bitmapInfo)
if context == nil {
return
}
let imageRef = context?.makeImage()
let scaledWidth = Int(Double(width!) / 1.5)
let scaledHeight = Int(Double(height!) / 1.5)
let resizeCtx = CGContext.init(data: nil, width: scaledWidth, height: scaledHeight, bitsPerComponent: bitsPerComponent, bytesPerRow: bytesPerRow!, space: colorSpace, bitmapInfo: bitmapInfo)
resizeCtx?.draw(imageRef!, in: CGRect(x: 0, y: 0, width: scaledWidth, height: scaledHeight))
resizeCtx?.interpolationQuality = .low
let resizedImgRef = resizeCtx?.makeImage()
let imageRep = NSBitmapImageRep(cgImage: resizedImgRef!)
let finalData = imageRep.representation(using: .jpeg, properties: [NSBitmapImageRep.PropertyKey.compressionFactor : compression])

Answer 2

Try this, change imageName to what you want, and save it in any Directory
func convertToJPEG(image: UIImage) {
if let jpegImage = UIImageJPEGRepresentation(image, 1.0){
do {
//Convert
let tempDirectoryURL = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true)
let newFileName = "\(imageName.append(".JPG"))"
let targetURL = tempDirectoryURL.appendingPathComponent(newFileName)
try jpegImage.write(to: targetURL, options: [])
}catch {
print (error.localizedDescription)
print("FAILED")
}
}else{
print("FAILED")
}
}