size of recoverd image gets increased [closed]

asked 2018-06-23 03:46:26 -0500

vishalsira gravatar image

updated 2018-06-23 03:58:16 -0500

berak gravatar image

I am reading image from this method

        Mat originalImage = Highgui.imread(path);
        byte[] imageInByte = new byte[(int) ( * originalImage.channels())];
        originalImage.get(0, 0, imageInByte);

        TYPE = originalImage.type();
        HEIGHT = originalImage.height();
        WIDTH = originalImage.width();

while recovering image i'm using

    Mat mat = new Mat(HEIGHT, WIDTH , TYPE);
    mat.put(0, 0, bytesArrayForImage);
    String filename = Path;
    Highgui.imwrite(filename, mat);

by using these 2 methods i'm getting image of large size and the difference in between these 2 images which i'm getting is only bit depth i'm not getting how to resolve it

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Closed for the following reason the question is answered, right answer was accepted by berak
close date 2018-06-23 05:40:25.998313


which opencv version is it ?

can you edit it a bit, so the code compiles / can be reproduced ?

(i also cannot reproduce it, using 3.4.1 / 4.0.0)

berak gravatar imageberak ( 2018-06-23 04:05:19 -0500 )edit

i'm using 3.4.0 version of opencv

vishalsira gravatar imagevishalsira ( 2018-06-23 04:12:44 -0500 )edit

oh, wait, did you mean the size on disk ? (not W/H ?)

this entirely depends on file type and compression params passed to imwrite()

berak gravatar imageberak ( 2018-06-23 04:16:43 -0500 )edit

yes size on disk gets double and in properties of my file byte depths also gets increased by 3 times

vishalsira gravatar imagevishalsira ( 2018-06-23 04:19:24 -0500 )edit

bit depth of original image is 8 and reconstructed image's bit depth is 24

vishalsira gravatar imagevishalsira ( 2018-06-23 04:20:41 -0500 )edit

Highgui.imread(path); <-- this is from opencv2.4, not 3.4 and it will force reading in a 24bit image.

to read a grayscale one use

Highgui.imread(path, CV_LOAD_IMAGE_GRAYSCALE);

(if you're using outdated 2.4), for 3.x it would be:

Imgcodecs.imread(path, IMREAD_GRAYSCALE);
berak gravatar imageberak ( 2018-06-23 04:26:24 -0500 )edit

i'm using 3.4.0 version of opencv

please check again. it would be Imgcodecs, not Highgui, then.

berak gravatar imageberak ( 2018-06-23 04:28:24 -0500 )edit

It is Highgui, because when i'm tried with Imgcodecs it gives error

vishalsira gravatar imagevishalsira ( 2018-06-23 04:33:52 -0500 )edit

so it's 2.4, not 3.4.0.

however it will behave the same. if you want to read in a grayscale image, use the CV_LOAD_IMAGE_GRAYSCALE flag ( IMREAD_GRAYSCALE for 3.x)

berak gravatar imageberak ( 2018-06-23 04:57:55 -0500 )edit

its woring thanks

vishalsira gravatar imagevishalsira ( 2018-06-23 05:00:44 -0500 )edit