Incorrect image from RGBA data [closed]

asked 2020-03-29 13:14:18 -0500

Defloyd gravatar image

Hello, Iam using opencv4nodejs, Where i am creating a Mat with raw RGBA data (1440x1920)

this.mat = new cv.Mat(buff, width, height, cv.CV_8UC4);

this looks to go OK:

Mat {
  step: 7680,
  elemSize: 4,
  sizes: [ 1440, 1920 ],
  empty: 0,
  depth: 0,
  dims: 2,
  channels: 4,
  type: 24,
  cols: 1920,
  rows: 1440

When i try to write this back to an image with imwrite

const BGR = this.mat.cvtColor(cv.COLOR_RGBA2BGR);
cv.imwrite(`./server/vision/opencv/assets/img${this.count}.jpg`, BGR);

i get the following image, which has 4 vertical sections? Iam not sure where the problem is, reading or writing of the Mat

image description

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Closed for the following reason question is off-topic or not relevant by berak
close date 2020-03-29 14:25:53.946686


sorry to say so, but there's no support for opencv4nodejs from opencv, it's an entirely seperate 3rdparty effort, and we cannot help you from here

berak gravatar imageberak ( 2020-03-29 14:25:36 -0500 )edit

ah ok,

anyway i found out my stupid mistake, i had width and height mixed up with rows and cols.

if u do that on normal opencv, u will probably get the same output :)

Defloyd gravatar imageDefloyd ( 2020-03-29 14:36:12 -0500 )edit

if u do that on normal opencv, u will probably get the same output


berak gravatar imageberak ( 2020-03-30 03:49:29 -0500 )edit