instock Posted January 7, 2021 Share Posted January 7, 2021 My son is doing remote learning and his teacher sends a bunch of png worksheets. She doesn't know how to use a scanner, so the worksheets always have dark gray backgrounds instead of white. When I print them out and my son tries to write on them with a pencil, it's really hard to even see what he's writing. I try to clean them up by playing with the contrast, brightness, and "sharpen". It sort of works, but I'm just hacking. Is there a better way for a noob to do this? Quote Link to comment Share on other sites More sharing options...
ardneh Posted January 7, 2021 Share Posted January 7, 2021 Brightness / Contrast would be my first go-to. If you post a link to one of the pages, you could get more tailored advice. https://imgbox.com Quote Link to comment Share on other sites More sharing options...
instock Posted January 7, 2021 Author Share Posted January 7, 2021 Thanks. This is an example of an original and what it looks like when I play with the brightness and contrast. You can still see the gray in the lower right, but I'm already losing all kinds of detail. https://imgbox.com/g/y8QXwd8MeY Quote Link to comment Share on other sites More sharing options...
Reptillian Posted January 7, 2021 Share Posted January 7, 2021 (edited) I would just resort to tracing with .svg and .pdf to do those. There is also OCR readers to consider. And then there is some other solution like afre text contrast in gmic-qt which was designed for tasks like these. Edited January 7, 2021 by Reptillian Quote G'MIC Filter Developer I am away from this forum for undetermined amount of time: If you really need anything related to my PDN plugin or my G'MIC filter within G'MIC plugin, then you can contact me via Paint.NET discord, and mention me. Link to comment Share on other sites More sharing options...
Pixey Posted January 7, 2021 Share Posted January 7, 2021 So I tried this, but not sure if it's what you want. 1. Use the color picker to select haflway gray. Click for larger 2. Use the Grim Color Reaper to remove the color. Quote How I made Jennifer & Halle in Paint.net My Gallery | My Deviant Art "Rescuing one animal may not change the world, but for that animal their world is changed forever!" anon. Link to comment Share on other sites More sharing options...
MXI Posted January 7, 2021 Share Posted January 7, 2021 (edited) I remember using a multistep processing for this: - convert to grayscale; - invert image; - isolate the background levels in a separate layer (remove high-contrast stuff such as text with Median filter); - substract it from the image; - invert back; - clean up remaining noise with Levels filter (histogram there is also helpful to evaluate the quality of cleanup). I later found that there is actually one existing filter that can achieve about the same effect much easier and faster: Use Effects > Artistic > Pencil Sketch! Edited January 7, 2021 by MXI 2 2 Quote My content: custom shapes FRs: selections lists stored within pdn file | HSL and/or pluggable Colors box Link to comment Share on other sites More sharing options...
Reptillian Posted January 7, 2021 Share Posted January 7, 2021 Here's my attempt with G'MIC-QT 1. Details->Local Normalization 2. Repair-> Clean Text Quote G'MIC Filter Developer I am away from this forum for undetermined amount of time: If you really need anything related to my PDN plugin or my G'MIC filter within G'MIC plugin, then you can contact me via Paint.NET discord, and mention me. Link to comment Share on other sites More sharing options...
ardneh Posted January 7, 2021 Share Posted January 7, 2021 (edited) Here's what I came up with: https://imgbox.com/MuzEIUe0 Pencil Sketch at default. Gaussian Blur, radius 1. Duplicate layer. Set top layer to Multiply blend mode. Duplicate that layer. Image > Flatten Brightness / Contrast Brightness 10 Contrast 10 Duplicate layer. Set top layer to Multiply blend mode. Merge layers. Edited June 17, 2021 by ardneh Quote Link to comment Share on other sites More sharing options...
MXI Posted January 7, 2021 Share Posted January 7, 2021 My take: https://imgbox.com/zjgE42Y1 1. Resize 400% (working in higher resolution might help in multiple ways. The sample was too small); 2. Sharpen max (to make text thicker); 3. Sharpen max (one might be enough, but I found this to be a bit better); 4. Pencil Sketch (tip size max, range min); 5. Resize 50% (still 200% from the source, helps with the next step a bit); 6. Levels (adjust input white to remove as much remaining noise while retaining required details, may also adjust output middle point). 1 Quote My content: custom shapes FRs: selections lists stored within pdn file | HSL and/or pluggable Colors box Link to comment Share on other sites More sharing options...
Scooter Posted January 7, 2021 Share Posted January 7, 2021 While all of these worthy answers/suggestions/ideas are totally with in the spirit of help and cooperation found on Paint.NET, not at all surprising. But I would humbly suggest that instock reach out to the teacher and offer to help her/him with understanding How To Scan a page more successfully. I would venture that help would bring joy to all the students involved today and in future. 2 1 Quote Scooter Age is only a number --in my case a Really BIG number, but there you have it When the prefect paint.net image is created, I will still be wondering "How they Do that?"- sigh☺️ Link to comment Share on other sites More sharing options...
instock Posted January 8, 2021 Author Share Posted January 8, 2021 4 hours ago, Scooter said: While all of these worthy answers/suggestions/ideas are totally with in the spirit of help and cooperation found on Paint.NET, not at all surprising. But I would humbly suggest that instock reach out to the teacher and offer to help her/him with understanding How To Scan a page more successfully. I would venture that help would bring joy to all the students involved today and in future. I thought about it. I'm not really that smart with that stuff, though. Maybe I could futz with it. But trying to debug it remotely on whatever setup she has? Just a little too far outside my wheelhouse. 1 Quote Link to comment Share on other sites More sharing options...
instock Posted January 8, 2021 Author Share Posted January 8, 2021 I think that pencil sketch effect does exactly what I was hoping for. I'm not looking for perfection. It's just a worksheet. Some of you guys have obviously taken it to the next level and then some. I'll play around with it and see how it works going forward. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.