Writing Images using QImage from 2D Array

[kaydknight]

Hi I have a very simple question, suppose that I have a 2D 50 x 50 array consisting of say, pixel values (0-255), and I want to save this as image, how do I actually do it?

I've tried:

QImage image;
QRgb value;
 
// a 2d array named arr with size 50 x 50 including its values was declared earlier
 
for (int i=0;i<maxwidth;i++)
{
	for (int j=0;j<maxheight;j++)
	{
		// set the rgb value based on arrs' value
		// set them all the same to make em grayscale?
		value = qRgb(arr[i][j],arr[i][j],arr[i][j]);	
		image.setPixel(i,j,value);
	}
}
 
image.save("test.jpg",".jpg");

QImage image;
QRgb value;

// a 2d array named arr with size 50 x 50 including its values was declared earlier

for (int i=0;i<maxwidth;i++)
{
	for (int j=0;j<maxheight;j++)
	{
		// set the rgb value based on arrs' value
		// set them all the same to make em grayscale?
		value = qRgb(arr[i][j],arr[i][j],arr[i][j]);	
		image.setPixel(i,j,value);
	}
}

image.save("test.jpg",".jpg");

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I suspect there is more than just setting the pixel values using QImage::setPixel. Am I missing something else? Thanks in advance.

[kaydknight]

Opps, I already got the answer, haha a simple mistake, but just to share, I should use the overloaded constructor of QImage to specify the width, height and format

QImage image(50,50,QImage::Format_RGB32);   // use the overloaded constructor
QRgb value;
 
// a 2d array named arr with size 50 x 50 including its values was declared earlier
 
for (int i=0;i<maxwidth;i++)
{
	for (int j=0;j<maxheight;j++)
	{
		// set the rgb value based on arrs' value
		// set them all the same to make em grayscale?
		value = qRgb(arr[i][j],arr[i][j],arr[i][j]);	
		image.setPixel(i,j,value);
	}
}
 
image.save("test.jpg",".jpg");

QImage image(50,50,QImage::Format_RGB32);   // use the overloaded constructor
QRgb value;

// a 2d array named arr with size 50 x 50 including its values was declared earlier

for (int i=0;i<maxwidth;i++)
{
	for (int j=0;j<maxheight;j++)
	{
		// set the rgb value based on arrs' value
		// set them all the same to make em grayscale?
		value = qRgb(arr[i][j],arr[i][j],arr[i][j]);	
		image.setPixel(i,j,value);
	}
}

image.save("test.jpg",".jpg");

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