Create UIImage from RGBA data in swift

Question

I have a pixel array from which UIImage needs to be created. The pixel array uses 4 bytes for each pixel in RGBA format. i.e. 00000000 - is black transparent and 000000ff - is black opaque.

The UIImage is to be created using swift and xcode 6.3 or greater.

Need to loop through the pixel array, get every four bytes for each pixel and create image from the pixels.

Could see objective c references, but not clear code sample for swift.

Where are the objective c reference ? I can translate them in swift for you — Stefan Scoarta, Jul 05 '15 at 06:21
Check out this question. http://stackoverflow.com/q/30958427/1630618 — vacawama, Jul 05 '15 at 10:07

score 1 · Answer 1 · answered Mar 23 '16 at 10:17

Here is a sample that I use to create CGImages from an RGBA byte array:

struct m_RGBColor // My own data-type to hold the picture information
{
    var Alpha: UInt8 = 255
    var Red:   UInt8 = 0
    var Green: UInt8 = 0
    var Blue:  UInt8 = 0
}

var pixelArray: [m_RGBColor] = [m_RGBColor]()
var pixelColor: m_RGBColor = m_RGBColor()

for y in 0 ..< height // Height of your Pixture
{
    for x in 0 ..< width // Width of your Picture
    {
        onePixel.Alpha = 0 // Fill one Pixel with your Picture Data
        onePixel.Red   = 0 // Fill one Pixel with your Picture Data
        onePixel.Green = 0 // Fill one Pixel with your Picture Data
        onePixel.Blue  = 0 // Fill one Pixel with your Picture Data
        pixelArray.append(onePixel)
    }
}

let bitmapCount: Int = pixelArray.count
let elmentLength: Int = sizeof(m_RGBColor)
let render: CGColorRenderingIntent = CGColorRenderingIntent.RenderingIntentDefault
let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
let bitmapInfo: CGBitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedFirst.rawValue)
let providerRef: CGDataProvider? = CGDataProviderCreateWithCFData(NSData(bytes: &pixelArray, length: bitmapCount * elmentLength))
let cgimage: CGImage? = CGImageCreate(width, height, 8, 32, width * elmentLength, rgbColorSpace, bitmapInfo, providerRef, nil, true, render)
if cgimage != nil
{
    // You have success, the Image is valid and usable
}

Create UIImage from RGBA data in swift

1 Answers1