Hdmi Input four corner adjustment

Can some one teach me how to correct corners in firestick. If pico max team was saying to correct it from source.

4 corner adjustment is not possible with HDMI input, only vertical keystone.

with the official apps on the PPM there is 4 corner adjustment possible.

It won’t work because HDMI input bypasses the OS and since 4 corner correction is the OS, it can’t be done. It is better for image quality based on my understanding.

I am looking forward to the new update (and all subsequent updates) that will help with bringing the apps to perfect working conditions. The goal is to have a portable projector and HDMI sticks really take away from the portability.

I believe what they mean by correct it from the source is actually adjust your projector so that it is centered to the screen. virticle correction is still possible.


FireTV only has a limited-range digital zoom adjustment (no 4-corner). You can adjust it by going to Settings > Display & Sound > Display > Calibrate Display.


As they said: do it on your source. (relocate your PPM projector… :crazy_face:)

The issue is that four corner adjustment is a software correction, that adjusts the image being projected in software. It is not a physical correction or realignment of the optical components within the projector. This software correction is part of the Android operating system and so any video being played through Android (such as through an App or through mirroring) can be corrected. Any video source that bypasses Android - such as HDMI - cannot be corrected. In this case, Philips’ advice is to physically move the projector or, if using an external device use any software controls it may have to adjust the image.

Since it can be done by PPM apps, it means Philips can do something about it. They should add a software plug-in (to the HDMI data source or well known video players) to solve this issue. It was promised during the campaign.

Thank you.

This will not work. Anything not going through the internal android software (HDMI, USB-C) cannot have any image correction applied to it like 4-corner correction. This will not be updated.

I’d like a list of “sources” which are capable of 4 CC on their own.

Why is this in “Feature suggestions”?? 4-corner for HDMI input can not and will not be done so such Feature suggestion is pointless. Please move this to Technical or another category. Having votes in this category may give some users false feeling that this is possible if lots of people vote for it. And that would be misleading.

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Is there an android TV source that can do it?


Philips in the latest update already told us that 4 corner adjustment for Hdmi and usb type-c is not possible.

FYI Philips update #18

Hope this can answer your question :kissing:

I too believe the same. This is not first thing that ppm was doing. Other projectors doing it without compromise in video quality

I can guarantee that no other projectors are doing it without compromising video quality unless they are using an optical correction. And in that case, they will not be a $500 pocket-sized device.

Please give an example for projector with such size that has optical correction. Unless you come from far future I can bet that either you will not give such example or whatever you give will be using software correction which ALWAYS decrease image quality.

500$ was early bird’s discount. Its not the actual price. Picture is the soul for the cinema. It doesn’t make any sense to me you saying portability is the reason for irregular hdmi input.

Well, I’m afraid you can’t get around price and physics, however much you would like to do so. Optical corrections require more complex optics (and thus increased size) and are a lot more expensive (so cost more). No amount of wishful thinking will change that. But there’s nothing stopping you returning the PicoPix Max and buying one of the projectors you claim exist.

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Optical corrections work great but as you say, not going to be available at this price point and size.

First time I evaluated the TI DMD digital V keystone feature was when I got my first 1080p DMD projector (the Optoma HD81) back in 2007. As that projector was based on a 4:3 (or 5:4 can’t remember) chassis it had more than 100% offset (the bottom of the image was located quite a bit above the projector) and I really wanted to ceiling mount it with the image as close to the ceiling as possible. This would need keystone adjustment by a few degrees but I had to disable it almost immediately. Straight lines becomes jagged because the still fairly limited resolution of 1080p. I had to solve it by moving the screen down some and accepting a small amount of residual keystone distorsion. That’s an image anomaly that’s a lot easier for me to accept than all the jagged edges of digital correction. The 4-corner correction happening in a reasonably modern GPU can filter and smooth the edges to reduce the jagged edges but it will result in a soft image.

I think people expect too much from a portable pico projector, but on the other hand the IGG story did include 4-corner correction with no limitations mentioned as a feature so I guess there are complaints just because it changed. I for one won’t enable any of the digital corrections for my portable/temporary use cases, I would just try to obtain a reasonably straight projection and leave it at that. The perceived image squareness will depend on where you sit in relation to the projector anyway so you’re not going to solve it for everyone (if multiple people are watching).

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I think with the info given by the IGG campaign and the latter info of the needed PCB correction for this feature, one might think that the planned feature would have been handled by the DMD pipeline, which would have brought a hardware based 4CC not just a software one.
But that’s just an assumption and unfortunately we will most likely never know.