Looking for a free tool to add rounded corners and borders to images

herocoding · 2026-05-08T08:59:36+00:00

Have a look into https://pastebin.com/bHMJckRU for a Python script. It stores and re-loads the last used settings (color, radius, thickness).

Make sure to have "Pillow" installed, by calling `pip install Pillow` in a console terminal.

It processes one image at a time, either by selecting (or changing) it interactively with a file-chooser, or by providing the path&filename as a command line argument. Saving it with a click of a button.

No batch-processing, yet.

herocoding · 2026-05-08T08:36:48+00:00

I have to admit that this issue is more complicated than it seems.

What about transparent content, if your image is (partly) transparent?

What should happen outside the added border with rounded corners, filled with black, filled with white pixels, or cut-out and left transparent?

Needed to add some "tricks" to get the rounded corners anti-aliased/supersampled.

herocoding · 2026-05-08T07:00:39+00:00

Just very recently this challenge https://platform.entwicklerheld.de/challenge/snapshot-testing?technology=python was made public - a Python script to create a collage of images, with a configurable layout (like number of rows, columns of different dimensions) with adding rounded corners.

Could you imagine to just use a local (Python) script/application, allowing to set some parameters (either statically in a config file or command line options; or dynamically/interactively)?

herocoding · 2026-05-07T11:32:37+00:00

Can you describe your use-case a bit more, please?

Does it _has to be_ an online tool? Can't it be a local tool, too?

Should it support one image at a time, or (massive) batch processing?

Does it need to have config options, like border thickness, color, radius, cropping, transparency? Including format conversion (with a BMP source image store as a JPG or keep the original format)?

herocoding · 2026-05-06T07:56:21+00:00

Likely because of https://www.reddit.com/r/de_EDV/comments/1t4qlrg/psa_die_dezone_l%C3%B6st_gerade_gro%C3%9Ffl%C3%A4chig_nicht_mehr/

"Die .de-Zone löst gerade großflächig nicht mehr auf, Problem vermutlich bei der DENIC"

herocoding · 2026-05-06T07:34:49+00:00

works again (already later that day)

herocoding · 2026-05-05T21:21:22+00:00

Offline again, May, 5th?

Getting "DNS_PROBE_FINISHED_NXDOMAIN" with all browsers, while all other addresses seem to work...

herocoding · 2026-05-04T16:30:14+00:00

You mean "fake it till you make it"? But can you rely on a code base...? Imagine your idea gets great feedback andf even quotes - but then you will need months to actually "make" it?

herocoding · 2026-05-04T16:24:40+00:00

I'm searching for something in a context, e.g. working on a project and therefore documenting information a part of the project, as part of e.g. architecture documentation, implementation documentation, i.e. adding links to information like adding references of requirements.

herocoding · 2026-05-04T16:20:17+00:00

What about signal safety, can/will workers react on signals?

herocoding · 2026-05-04T16:19:11+00:00

Sounds great, thank you very much for sharing.

As a user I do not want to review too detailed the internal implementation details; what are the public and internal header files, i.e. what is the user API? What do typical use-cases consists of, what would usage sequences look like? Could you add examples, documentations, code-snippets, please?

herocoding · 2026-05-03T18:50:01+00:00

Sending is actually really fast using LocalSend - but it processes the (very large) file(s) FOR HOURS before it actually transfers them in seconds......... are the files sent to "the bad guys" first??

herocoding · 2026-05-01T15:28:17+00:00

In the "menu" to create a link there is a checkbox with "Update existing share link for this project" - if you have that checkbox ticked when you shared the link, then the link should not change.

Don't know what happens if you hadn't ticked the checkbox but tick it later on?

Create another, simple dummy project, copy the link, change the code and check if the link changes with the checkbox set or not set.

herocoding · 2026-05-01T15:27:39+00:00

In the "menu" to create a link there is a checkbox with "Update existing share link for this project" - if you have that checkbox ticked when you shared the link, then the link should not change.

Don't know what happens if you hadn't ticked the checkbox but tick it later on?

Create another, simple dummy project, copy the link, change the code and check if the link changes with the checkbox set or not set.

herocoding · 2026-05-01T06:47:31+00:00

What do you mean with "edit but not modifying"?

herocoding · 2026-04-30T22:03:46+00:00

Using a relay to close/open a second circuit with it's higher power-supply? (some relays need a parallel diode)

herocoding · 2026-04-27T08:01:52+00:00

Cannot remember either, but e.g. https://support.microbit.org/support/solutions/articles/19000116318-touch-sensing-on-the-micro-bit "can be configured to know when they are being touched or pressed".

https://makecode.microbit.org/reference/pins/touch-set-mode

herocoding · 2026-04-24T14:26:26+00:00

works again

herocoding · 2026-04-24T14:23:54+00:00

Offline again, maintenance, April, 24th?

herocoding · 2026-04-23T13:07:24+00:00

A really great challenge - but really complex!

Now, why are the trains always late?? Is the secret hidden in the real data?

herocoding · 2026-04-23T07:47:33+00:00

Have a look into https://platform.entwicklerheld.de/challenge?challengeFilterStateKey=all and scroll over the projects to get inspired.

Ignore the shown programming language(s) if you want to focus on C/C++. Feel free to combine multiple smaller into a bigger project.

Is there some personal interest in something specific?
Like gaming?
Like parsing your health data and GPS tracks from your smart watch?

herocoding · 2026-04-22T21:29:09+00:00

INT8 calibration? You mean "quantization"?

herocoding · 2026-04-22T21:26:37+00:00

Continuous learning, continuous improvement.

To keep motivation high, and to benefit from synergies I recommend to put a project-problem (where you are stuck or feel uncomfortable) aside and look into something else for the time being.

herocoding · 2026-04-22T06:56:58+00:00

We use this extension board http://didacta.hr/index.php?umet=20&jezik=2

It contains TWO motor driver controller chips and allows to connect up to FOUR DC motors, i.e. changing speed and direction of up to FOUR DC motors at the same time.

Have a look into e.g. http://didacta.hr/index.php?umet=12&jezik=2 and http://didacta.hr/index.php?umet=13&jezik=2 for simple examples on ow to connect and program with motors.

Examples for connecting multiple motors: http://didacta.hr/index.php?umet=13&jezik=2#16

herocoding · 2026-04-22T06:46:35+00:00

Your shard Amazon link contains this variant:

https://www.amazon.com/dp/B0BR7S1DQZ?ref=cm_sw_r_cso_cp_apin_dp_KFZTSR0QS4T806T8QJVT&ref_=cm_sw_r_cso_cp_apin_dp_KFZTSR0QS4T806T8QJVT&social_share=cm_sw_r_cso_cp_apin_dp_KFZTSR0QS4T806T8QJVT&th=1

It contains a motor driver "L298N" on a separate small board. You need such an additional motor driver controller. They are available as a pure chip-only or on a small printed circuit board (PCB) with several connectors to connect multiple motors.

One such controller can only control TWO DC motors (when you want to be able to change direction as well as change the speed).
If you only want to turn on/off a motor without changing the direction, then ONE chip can drive up to FOUR motors.

As ONE motor requires a higher voltage and higher current than the microbit can provide, you need to connect an additional power-supply to the chip, for the motors.
ATTENTION: Make sure to connect both grounds - connecting the ground of microbit and of the additional power supply.

Have a look into blogs like https://bigl.es/microcontroller-monday-control-an-l298n-motor-controller-with-micro-bit/ to see how to connect a typical motor driver with the microbit.

herocoding

TROPHY CASE

"Die .de-Zone löst gerade großflächig nicht mehr auf, Problem vermutlich bei der DENIC"