Pseudo code for super resolution?

Hi Every one,

I am working on some images which are not clear and I want to increase their resolution to very much extent. I would like to apply this Super resolution algorithm to them to see whether this works for them or not. I have seen some codes but I didn't understand what's really happening in that code. If any one could explain me what are the steps to find out this super resolution?

Regards, Hari.

Answer 1

[Hari]

Hi,

I understand that you are working with unclear or low-resolution images and would like to enhance their quality using a super-resolution algorithm. You are also looking for a clear explanation of the steps involved in applying such an algorithm.

I assume you are referring to single-image super-resolution and aim to apply it using MATLAB, potentially using available models like SRCNN.

In order to apply super-resolution on low-resolution images, you can follow the below steps:

Step 1: Load the low-resolution image

Use the "imread" function to read your input image into MATLAB.

imgLR = imread('your_low_res_image.jpg');

Step 2: Convert the image to YCbCr color space

Super-resolution models like SRCNN work on the luminance channel.

imgYCbCr = rgb2ycbcr(imgLR);
imgY = imgYCbCr(:,:,1);  % Extract luminance channel

Step 3: Resize the image (optional pre-upscaling)

Use "imresize" to upscale the image, which serves as input to the model.

imgYup = imresize(imgY, 2, 'bicubic');

Step 4: Apply a pretrained super-resolution model

Use a model like SRCNN available in MATLAB via "deep learning toolbox".

net = importONNXNetwork('srcnn.onnx','OutputLayerType','regression');
imgYupSingle = single(imgYup)/255;
imgSR = predict(net, imgYupSingle);

Step 5: Combine and visualize the result

Merge the enhanced luminance with original chrominance and convert back to RGB.

imgYCbCr(:,:,1) = uint8(imgSR*255);
imgHR = ycbcr2rgb(imgYCbCr);
imshow(imgHR);

Refer to the documentation of "imresize" function to know more about interpolation options:

https://www.mathworks.com/help/images/ref/imresize.html

Refer to the documentation of "importONNXNetwork" to learn how to load pretrained models:

https://www.mathworks.com/help/deeplearning/ref/importonnxnetwork.html

Refer to the documentation of "predict" for applying the network to an image:

https://www.mathworks.com/help/deeplearning/ref/dlnetwork.predict.html

Hope this helps!