How to make an image clearer?

Question

I usually use two techniques to make a image clearer:

1. Use a High Pass filter, then adjust the Layer Mode to be Soft Light
2. Use the Sharpen module in Camera raw

But these methods don't work in these two images:

I hope to make them clearer(the outline is distincter, the noise is lesser). Here is an example of what I'm looking for:

Are there any useful techniques that can help?

Answer 1

What you want is a mixture of levels adjustment and curves adjustment, which will give you the following result (left side: original image, right side: improved version):

I used both methods to improve the contrast in your image, which, to human eyes, makes the image sharper as well. Since I don't know what you're looking for in these images (which shades and nuances are important), I applied them very carefully; you can use them much more radically to put more contrast in there (at the expense of losing some nuances in the middle tones).

While the levels + curves adjustments effectively do the same thing as the sledgehammer method of "enhance contrast + brightness", they give you much more control over what you're doing, so you can put bright and dark tones exactly where they belong.

For instructions on how to use both tools in Photoshop, just follow this links:
https://helpx.adobe.com/photoshop/using/levels-adjustment.html
https://helpx.adobe.com/photoshop/using/curves-adjustment.html

For anyone else reading this, please note that both tools are also available in Open Source Software such as Gimp, so there's no need to buy expensive proprietary software if you don't want to. My two versions above were made using Gimp.

Answer 2

To my eye, the top image you posted lacks contrast. To help with the noise I've used a wavelet de-noise filter and applied a selective Gaussian blur. I've also increased the contrast with this image and now it looks 'clearer' to me.

The 10µm text at the bottom is difficult to read. Consider omitting that from the source image and adding it as the last step in post-processing if you are able.

Answer 3

In the jpeg from the question, most of the dynamic range is 'wasted' by which I mean that there are very few black pixels and very few white pixels...so few that that black and white pixels are probably more representative of noise than interesting information.

This image represents raising the the black point and lowering the white point so that there are more black and white pixels respectively. There are also more dark gray pixels. Absent criteria for interpretation, it may or may not be better than the original image.

This version has substantially more sharpening. Absent criteria for interpretation, it may or may not be better than other techniques.

Notes:

1. Working from jpeg does not allow much latitude for remapping greyscale data relative to having a RAW file. Because the starting point is only eight bits.

2. I processed the image in Darktable using the Levels tool to adjust black and white points until some meaningful number of pixels were clipped dark and bright.

3. Darktable's Sharpness tool was applied to produce the second image.