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Save Alby-o/fe87e35bc21d534c8220aed7df028e03 to your computer and use it in GitHub Desktop.
// imgLib -> Image package from https://pub.dartlang.org/packages/image | |
import 'package:image/image.dart' as imglib; | |
import 'package:camera/camera.dart'; | |
Future<List<int>> convertImagetoPng(CameraImage image) async { | |
try { | |
imglib.Image img; | |
if (image.format.group == ImageFormatGroup.yuv420) { | |
img = _convertYUV420(image); | |
} else if (image.format.group == ImageFormatGroup.bgra8888) { | |
img = _convertBGRA8888(image); | |
} | |
imglib.PngEncoder pngEncoder = new imglib.PngEncoder(); | |
// Convert to png | |
List<int> png = pngEncoder.encodeImage(img); | |
return png; | |
} catch (e) { | |
print(">>>>>>>>>>>> ERROR:" + e.toString()); | |
} | |
return null; | |
} | |
// CameraImage BGRA8888 -> PNG | |
// Color | |
imglib.Image _convertBGRA8888(CameraImage image) { | |
return imglib.Image.fromBytes( | |
image.width, | |
image.height, | |
image.planes[0].bytes, | |
format: imglib.Format.bgra, | |
); | |
} | |
// CameraImage YUV420_888 -> PNG -> Image (compresion:0, filter: none) | |
// Black | |
imglib.Image _convertYUV420(CameraImage image) { | |
var img = imglib.Image(image.width, image.height); // Create Image buffer | |
Plane plane = image.planes[0]; | |
const int shift = (0xFF << 24); | |
// Fill image buffer with plane[0] from YUV420_888 | |
for (int x = 0; x < image.width; x++) { | |
for (int planeOffset = 0; | |
planeOffset < image.height * image.width; | |
planeOffset += image.width) { | |
final pixelColor = plane.bytes[planeOffset + x]; | |
// color: 0x FF FF FF FF | |
// A B G R | |
// Calculate pixel color | |
var newVal = shift | (pixelColor << 16) | (pixelColor << 8) | pixelColor; | |
img.data[planeOffset + x] = newVal; | |
} | |
} | |
return img; | |
} |
imglib.Image _convertBGRA8888(CameraImage image) {
return imglib.Image.fromBytes(
image.width,
image.height,
image.planes[0].bytes,
order: ChannelOrder.bgra,
);
}
Hi, 'img.data[index]' seems no longer use, how to modify the code when using convertYUV420ToImage?
Hi, 'img.data[index]' seems no longer use, how to modify the code when using convertYUV420ToImage?
I have the same problem
Hi, 'img.data[index]' seems no longer use, how to modify the code when using convertYUV420ToImage?
I have the same problem
Hi juanlabrador
I found a way and it's work well. Replace 'img.data[index]' to 'img.setPixelRgba(x, y, r, g, b, hexFF);'
Hi, 'img.data[index]' seems no longer use, how to modify the code when using convertYUV420ToImage?
I have the same problem
Hi juanlabrador
I found a way and it's work well. Replace 'img.data[index]' to 'img.setPixelRgba(x, y, r, g, b, hexFF);'
And what should go into each value?
imglib.Image _convertBGRA8888(CameraImage image) { return imglib.Image.fromBytes( image.width, image.height, image.planes[0].bytes, order: ChannelOrder.bgra, ); }
the image result is all broken.
@neoacevedo I used this function.
static imglib.Image convertBGRA8888ToImage(CameraImage cameraImage) {
return imglib.Image.fromBytes(
width: cameraImage.planes[0].width!,
height: cameraImage.planes[0].height!,
bytes: cameraImage.planes[0].bytes.buffer,
order: imglib.ChannelOrder.bgra,
);
}
I used this function.
static imglib.Image convertBGRA8888ToImage(CameraImage cameraImage) {
return imglib.Image.fromBytes(
width: cameraImage.planes[0].width!,
height: cameraImage.planes[0].height!,
bytes: cameraImage.planes[0].bytes.buffer,
order: imglib.ChannelOrder.bgra,
);
}
its working for iOS, but not on Android.
What imageFormatGroup did you use to create the Camera Controller?
federico-amura-kenility I think on Android you should use convertYUV420ToImage. I modify my class after update Image lib, please try this code.
part of object_detection;
/// ImageUtils
class ImageUtils {
///
/// Converts a [CameraImage] in YUV420 format to [image_lib.Image] in RGB format
///
static imglib.Image convertCameraImage(CameraImage cameraImage) {
if (cameraImage.format.group == ImageFormatGroup.yuv420) {
return convertYUV420ToImage(cameraImage);
} else if (cameraImage.format.group == ImageFormatGroup.bgra8888) {
return convertBGRA8888ToImage(cameraImage);
} else {
throw Exception('Undefined image type.');
}
}
///
/// Converts a [CameraImage] in BGRA888 format to [image_lib.Image] in RGB format
///
static imglib.Image convertBGRA8888ToImage(CameraImage cameraImage) {
return imglib.Image.fromBytes(
width: cameraImage.planes[0].width!,
height: cameraImage.planes[0].height!,
bytes: cameraImage.planes[0].bytes.buffer,
order: imglib.ChannelOrder.bgra,
);
}
///
/// Converts a [CameraImage] in YUV420 format to [image_lib.Image] in RGB format
///
static imglib.Image convertYUV420ToImage(CameraImage cameraImage) {
final imageWidth = cameraImage.width;
final imageHeight = cameraImage.height;
final yBuffer = cameraImage.planes[0].bytes;
final uBuffer = cameraImage.planes[1].bytes;
final vBuffer = cameraImage.planes[2].bytes;
final int yRowStride = cameraImage.planes[0].bytesPerRow;
final int yPixelStride = cameraImage.planes[0].bytesPerPixel!;
final int uvRowStride = cameraImage.planes[1].bytesPerRow;
final int uvPixelStride = cameraImage.planes[1].bytesPerPixel!;
final image = imglib.Image(width: imageWidth, height: imageHeight);
for (int h = 0; h < imageHeight; h++) {
int uvh = (h / 2).floor();
for (int w = 0; w < imageWidth; w++) {
int uvw = (w / 2).floor();
final yIndex = (h * yRowStride) + (w * yPixelStride);
// Y plane should have positive values belonging to [0...255]
final int y = yBuffer[yIndex];
// U/V Values are subsampled i.e. each pixel in U/V chanel in a
// YUV_420 image act as chroma value for 4 neighbouring pixels
final int uvIndex = (uvh * uvRowStride) + (uvw * uvPixelStride);
// U/V values ideally fall under [-0.5, 0.5] range. To fit them into
// [0, 255] range they are scaled up and centered to 128.
// Operation below brings U/V values to [-128, 127].
final int u = uBuffer[uvIndex];
final int v = vBuffer[uvIndex];
// Compute RGB values per formula above.
int r = (y + v * 1436 / 1024 - 179).round();
int g = (y - u * 46549 / 131072 + 44 - v * 93604 / 131072 + 91).round();
int b = (y + u * 1814 / 1024 - 227).round();
r = r.clamp(0, 255);
g = g.clamp(0, 255);
b = b.clamp(0, 255);
image.setPixelRgb(w, h, r, g, b);
}
}
return image;
}
}
After some trial and error, I found the perfect solution for iOS:
const IOS_BYTES_OFFSET = 28;
static Image _convertBGRA8888ToImage(CameraImage cameraImage) {
final plane = cameraImage.planes[0];
return Image.fromBytes(
width: cameraImage.width,
height: cameraImage.height,
bytes: plane.bytes.buffer,
rowStride: plane.bytesPerRow,
bytesOffset: IOS_BYTES_OFFSET,
order: ChannelOrder.bgra,
);
}
The other solution produced a 1088 wide image with a 8px black bar. By adding rowStride
and bytesOffset
, it is now 1080 width with no black bars.
I have no idea where the offset of 28 comes from. Does anyone know why 28 works?
@saad-palapa Does anyone know why 28 works?
Now that we know the answer, the explanation is rather easy. 28 bytes is 8 pixels of BGRA. The image in memory is 1088 pixel wide with a black bar before the first column (the illustration keeps the 8 "black" extra pixels, but does not go keep the real dimensions):
XXXXXXXX......................
XXXXXXXX.......... _ .........
XXXXXXXX........ _( )_ .......
XXXXXXXX....... (_(%)_) ......
XXXXXXXX......... (_)\ .......
XXXXXXXX............. | __ ...
XXXXXXXX............. |/_/ ...
XXXXXXXX............. | ......
XXXXXXXX............. | ......
XXXXXXXX......................
XXXXXXXX......................
By adding the offset, you feed to Image.fromBytes()
something like
......................XXXXXXXX
.......... _ .........XXXXXXXX
........ _( )_ .......XXXXXXXX
....... (_(%)_) ......XXXXXXXX
......... (_)\ .......XXXXXXXX
............. | __ ...XXXXXXXX
............. |/_/ ...XXXXXXXX
............. | ......XXXXXXXX
............. | ......XXXXXXXX
......................XXXXXXXX
......................
The function is smart enough to throw away the extra pixels on the right when the width
parameter is 1080 and rowStride
is 1088.
Hello, I meet another problem. Does anyone try to convert NV21 from cameraImage to image ?
Some device (Xiaomi, Motorola) will have the NV21 format. Anyone can help?
@rraayy you can see how this can be efficiently done with ffi on medium. The sample code is available at https://github.com/Hugand/camera_tutorial
@rraayy you can see how this can be efficiently done with ffi on medium. The sample code is available at https://github.com/Hugand/camera_tutorial
Thanks so much @alexcohn , I will try it with ffi!
federico-amura-kenility I think on Android you should use convertYUV420ToImage. I modify my class after update Image lib, please try this code.
This works on Android, thank you very much.
@rraayy Any luck converting NV21 to Image? I'm having the same difficulties. The NV21 formatted CameraImage object only has one plane.
@owjoh here @camsim99 claims that the issue with NV21 for Motorola and Xiaomi has been fixed in a recent CameraX implementation.
Alternatively, convertImage function could be tuned to handle single-plane images, but I don't know their actual layout.
can anyone help me with yuv420 to RGB conversion on iOS ?
About a few days of struggling with the CamerImage to Image conversion, I managed to improve the method to include paddnig on different devices. I tested on several devices, checking the conversion at different camera resolutions. And I think it works.
imglib.Image convertYUV420ToImage(CameraImage cameraImage) { final imageWidth = cameraImage.width; final imageHeight = cameraImage.height; final yBuffer = cameraImage.planes[0].bytes; final uBuffer = cameraImage.planes[1].bytes; final vBuffer = cameraImage.planes[2].bytes; final int yRowStride = cameraImage.planes[0].bytesPerRow; final int yPixelStride = cameraImage.planes[0].bytesPerPixel!; final int uvRowStride = cameraImage.planes[1].bytesPerRow; final int uvPixelStride = cameraImage.planes[1].bytesPerPixel!; final image = imglib.Image(imageWidth, imageHeight); for (int h = 0; h < imageHeight; h++) { int uvh = (h / 2).floor(); for (int w = 0; w < imageWidth; w++) { int uvw = (w / 2).floor(); final yIndex = (h * yRowStride) + (w * yPixelStride); // Y plane should have positive values belonging to [0...255] final int y = yBuffer[yIndex]; // U/V Values are subsampled i.e. each pixel in U/V chanel in a // YUV_420 image act as chroma value for 4 neighbouring pixels final int uvIndex = (uvh * uvRowStride) + (uvw * uvPixelStride); // U/V values ideally fall under [-0.5, 0.5] range. To fit them into // [0, 255] range they are scaled up and centered to 128. // Operation below brings U/V values to [-128, 127]. final int u = uBuffer[uvIndex]; final int v = vBuffer[uvIndex]; // Compute RGB values per formula above. int r = (y + v * 1436 / 1024 - 179).round(); int g = (y - u * 46549 / 131072 + 44 - v * 93604 / 131072 + 91).round(); int b = (y + u * 1814 / 1024 - 227).round(); r = r.clamp(0, 255); g = g.clamp(0, 255); b = b.clamp(0, 255); // Use 255 for alpha value, no transparency. ARGB values are // positioned in each byte of a single 4 byte integer // [AAAAAAAARRRRRRRRGGGGGGGGBBBBBBBB] final int argbIndex = h * imageWidth + w; image.data[argbIndex] = 0xff000000 | ((b << 16) & 0xff0000) | ((g << 8) & 0xff00) | (r & 0xff); } } return image; }
Does this work for iOS ?
Hi @prkhrv,
Please take a look at nv21 to Image
In my project, the solution is work for me.
i fix it with use image.setPixelRgb it got valid image
by
"
imglib.Image convertYUV420ToImage(CameraImage cameraImage) {
final imageWidth = cameraImage.width;
final imageHeight = cameraImage.height;
final yBuffer = cameraImage.planes[0].bytes;
final uBuffer = cameraImage.planes[1].bytes;
final vBuffer = cameraImage.planes[2].bytes;
final int yRowStride = cameraImage.planes[0].bytesPerRow;
final int yPixelStride = cameraImage.planes[0].bytesPerPixel!;
final int uvRowStride = cameraImage.planes[1].bytesPerRow;
final int uvPixelStride = cameraImage.planes[1].bytesPerPixel!;
final image = imglib.Image(width: imageWidth, height: imageHeight);
for (int h = 0; h < imageHeight; h++) {
int uvh = (h / 2).floor();
for (int w = 0; w < imageWidth; w++) {
int uvw = (w / 2).floor();
final yIndex = (h * yRowStride) + (w * yPixelStride);
// Y plane should have positive values belonging to [0...255]
final int y = yBuffer[yIndex];
// U/V Values are subsampled i.e. each pixel in U/V chanel in a
// YUV_420 image act as chroma value for 4 neighbouring pixels
final int uvIndex = (uvh * uvRowStride) + (uvw * uvPixelStride);
// U/V values ideally fall under [-0.5, 0.5] range. To fit them into
// [0, 255] range they are scaled up and centered to 128.
// Operation below brings U/V values to [-128, 127].
final int u = uBuffer[uvIndex];
final int v = vBuffer[uvIndex];
// Compute RGB values per formula above.
int r = (y + v * 1436 / 1024 - 179).round();
int g = (y - u * 46549 / 131072 + 44 - v * 93604 / 131072 + 91).round();
int b = (y + u * 1814 / 1024 - 227).round();
r = r.clamp(0, 255);
g = g.clamp(0, 255);
b = b.clamp(0, 255);
// Use 255 for alpha value, no transparency.
image.setPixelRgb(w, h, r, g, b);
}
}
return image;
}
"
but it still rotate the image by 270 degrees
you can fix it by rotate but i don't know how to to i just rotate in python backend !
imglib.Image _convertYUV420(CameraImage image) { var img = imglib.Image(image.width, image.height); // Create Image buffer final int width = image.width; final int height = image.height; final int uvRowStride = image.planes[1].bytesPerRow; final int uvPixelStride = image.planes[1].bytesPerPixel; const shift = (0xFF << 24); for(int x=0; x < width; x++) { for(int y=0; y < height; y++) { final int uvIndex = uvPixelStride * (x/2).floor() + uvRowStride*(y/2).floor(); final int index = y * width + x; final yp = image.planes[0].bytes[index]; final up = image.planes[1].bytes[uvIndex]; final vp = image.planes[2].bytes[uvIndex]; // Calculate pixel color int r = (yp + vp * 1436 / 1024 - 179).round().clamp(0, 255); int g = (yp - up * 46549 / 131072 + 44 -vp * 93604 / 131072 + 91).round().clamp(0, 255); int b = (yp + up * 1814 / 1024 - 227).round().clamp(0, 255); // color: 0x FF FF FF FF // A B G R img.data[index] = shift | (b << 16) | (g << 8) | r; } } return img; }@sikandernoori this way, it can be converted into color images, but it takes more than 1000ms to convert on a mobile phone with Snapdragon 870 CPU, and it will block the UI.
This works with 2 planes like the iPad camera does. But for me, "final int uvPixelStride = image.planes[1].bytesPerPixel;" is always null, so I cannot use this code. Any Idea what I can change if that is null?
@KevinCCucumber what device are you working with?
@KevinCCucumber what device are you working with?
@alexcohn I am using an ipad air 5th gen
@KevinCCucumber what does it report on ipad air 5th gen for image.planes[0].bytesPerPixel
? image.planes[1].bytesPerRow
?
Hi, is there any update here ? The new version of image library is working differently
i fix it with use image.setPixelRgb it got valid image
It fast that can handle 20-40 pic per sec
import 'package:image/image.dart' as imglib;
imglib.Image convertYUV420ToImage(CameraImage cameraImage) {
final imageWidth = cameraImage.width;
final imageHeight = cameraImage.height;
final yBuffer = cameraImage.planes[0].bytes;
final uBuffer = cameraImage.planes[1].bytes;
final vBuffer = cameraImage.planes[2].bytes;
final int yRowStride = cameraImage.planes[0].bytesPerRow;
final int yPixelStride = cameraImage.planes[0].bytesPerPixel!;
final int uvRowStride = cameraImage.planes[1].bytesPerRow;
final int uvPixelStride = cameraImage.planes[1].bytesPerPixel!;
final image = imglib.Image(width: imageWidth, height: imageHeight);
for (int h = 0; h < imageHeight; h++) {
int uvh = (h / 2).floor();
for (int w = 0; w < imageWidth; w++) {
int uvw = (w / 2).floor();
final yIndex = (h * yRowStride) + (w * yPixelStride);
// Y plane should have positive values belonging to [0...255]
final int y = yBuffer[yIndex];
// U/V Values are subsampled i.e. each pixel in U/V chanel in a
// YUV_420 image act as chroma value for 4 neighbouring pixels
final int uvIndex = (uvh * uvRowStride) + (uvw * uvPixelStride);
// U/V values ideally fall under [-0.5, 0.5] range. To fit them into
// [0, 255] range they are scaled up and centered to 128.
// Operation below brings U/V values to [-128, 127].
final int u = uBuffer[uvIndex];
final int v = vBuffer[uvIndex];
// Compute RGB values per formula above.
int r = (y + v * 1436 / 1024 - 179).round();
int g = (y - u * 46549 / 131072 + 44 - v * 93604 / 131072 + 91).round();
int b = (y + u * 1814 / 1024 - 227).round();
r = r.clamp(0, 255);
g = g.clamp(0, 255);
b = b.clamp(0, 255);
// Use 255 for alpha value, no transparency.
image.setPixelRgb(w, h, r, g, b);
}
}
return image;
}
but it still rotate the image by 270 degrees.
so you can fix it by rotate.
i don't know how to do so i just rotate in python backend !
but it work for me
@min23asdw: Does this rotate the image properly for you?
import 'package:image/image.dart' as imglib;
imglib.Image convertYUV420ToImage(CameraImage cameraImage) {
final imageWidth = cameraImage.width;
final imageHeight = cameraImage.height;
final yBuffer = cameraImage.planes[0].bytes;
final uBuffer = cameraImage.planes[1].bytes;
final vBuffer = cameraImage.planes[2].bytes;
final int yRowStride = cameraImage.planes[0].bytesPerRow;
final int yPixelStride = cameraImage.planes[0].bytesPerPixel!;
final int uvRowStride = cameraImage.planes[1].bytesPerRow;
final int uvPixelStride = cameraImage.planes[1].bytesPerPixel!;
// Create the image with swapped width and height to account for rotation
final image = imglib.Image(width: imageHeight, height: imageWidth);
for (int h = 0; h < imageHeight; h++) {
int uvh = (h / 2).floor();
for (int w = 0; w < imageWidth; w++) {
int uvw = (w / 2).floor();
final yIndex = (h * yRowStride) + (w * yPixelStride);
final int y = yBuffer[yIndex];
final int uvIndex = (uvh * uvRowStride) + (uvw * uvPixelStride);
final int u = uBuffer[uvIndex];
final int v = vBuffer[uvIndex];
int r = (y + v * 1436 / 1024 - 179).round();
int g = (y - u * 46549 / 131072 + 44 - v * 93604 / 131072 + 91).round();
int b = (y + u * 1814 / 1024 - 227).round();
r = r.clamp(0, 255);
g = g.clamp(0, 255);
b = b.clamp(0, 255);
// Set the pixel with rotated coordinates
image.setPixelRgb(imageHeight - h - 1, w, r, g, b);
}
}
return image;
}
This code has some deprecated classes for Flutter 3.7.1:
imglib.Image _convertBGRA8888(CameraImage image)
has to be rewritten because ofimglib.Image.fromBytes
doesn't accept direct parameters and the Format enum doesn't have the bgra value.