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MPast.1
Senior
September 11, 2021
Question

Jpeg or BMP pictures on TouchGFX

  • September 11, 2021
  • 5 replies
  • 1883 views

Hi all,

I would like to reduce space on my external resource file (store into an QSPI meory), using compressed pictures instead of PNG images. In my case, my microcontroller has JPEG Codec HW peripheral. Why is not possibile to load JPEG or BMP on TouchGFX?

Thanks

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5 replies

MM..1
Super User
September 12, 2021

PNG isnt stored is always converted to design colorspace.

MPast.1
MPast.1Author
Senior
September 13, 2021

So if don't wrong, it is not possible to add JPEG picture in the project?

In other words, the scope is to reduce external memory occupation: the first thing I was thinking is to use all compressed images and use integrated decoder to help the rendering on screen.

SO, I would like to found a way that allow the use of compressed images.

Have you got some idea?

MM..1
Super User
September 13, 2021

I dont see any real example for this, but you can combine libjpeg decoding with image cache .

QSPI is realy big, why you need jpeg here?

MPast.1
MPast.1Author
Senior
September 13, 2021

QSPI generally are very big, but sometimes not enough and they can become expensive.

I have a "big" project composed at the moment by 165 pictures and those required about 8MBytes of space.

0693W00000Dn2r2QAB.jpgIf tomorrow I will need to add some more pictures i will must to change the memory.

Instead , if touchgfx allow to manage also jpeg files the space involved by graphics contents can be reduce of 50% - 60% (maybe more).

In this case your final graphic will need only 3 or 4 Mbytes, instead of 8MB.

The internal decoder peripheral can decode easily and fastly the compressed picture and with DMA or passing from RAM can send to the Display.

Every PNG image is decoded similar to:

0693W00000Dn2tDQAR.jpgand this is automatically saved in ExtFlashSection (QUADSPI) by the externalLoader when I program the microcontroller.

I think it could be very useful if Touchgfx designer allowed all other image formats to be imported into the project. In this way, all resources can be transferred to the QSPI with a single programming

MM..1
Super User
September 15, 2021

Maybe you dont understand code and timing for decoding formats "all other" will make for example change screen to other screen with 10 your compressed images maybe took more seconds , but now with prepared image format for LCD this took 20ms.

And as i write you can write external reader support for jpeg manualy stored in QSPI.