Using different color format for source bitmap(RGBA8888) and framebuffer(RGB565)

Question

Hello,

In order to use GRADIENT image in our project, we are exploring this option.

Currently we are evaluating IMXRT117x 2D GPU for a particular use case (NO_BANDING option) , which is mentioned in chapter 2.1.2.1 in AN13075 (AN13075: i.MX RT1170 Heterogeneous Graphics Pipeline – Application Note (nxp.com)).

In this example, we need to select the source bitmap image in the target as RGBA8888 and framebuffer image format as RGB565. Can you please let us know if there is any option that allows us to do the same

 

Thanks,

Kavya

Answer 1

Hello Kavya,

in case you are using the Build Environment for iMXRT1170 with VGLite support, you can choose either an RGBA8888 framebuffer or an RGB565 framebuffer by selecting the corresponding attribute PlatformPackage within the Profile settings.

Within Embedded Wizard the supported bitmap resource formats are RGBA8888 (native), RGB565, Index8 or Alpha8.

In case you are using a native bitmap resource and choose the PlatformPackage NXP.iMX_RT_VGLite.RGB565 you can test your described scenario.

I hope this helps.

Best regards,

Manfred.

Comments

Hello Manfred,

I think we need more clarity in the question

"In this example, we need to select the source bitmap image in the target as RGBA8888 and framebuffer image format as RGB565. Can you please let us know if there is any option that allows us to do the same" 

- the source bitmap mentioned in the above statement is not the input image to Embedded Wizard, rather it is the input image to the GPU (which is saved in target flash in particular color format)

Can you please clarify based on this context

Regards,

Kavya

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Hello Kavya,

in case you select a PlatformPackage with RGB565 (e.g. NXP.iMX_RT_VGLite.RGB565), the framebuffer will have the color format RGB565. This means, all graphics operations into this framebuffer will have this destination color format.

In case you define a bitmap resource as native, it will be generated as RGBA8888 and provided as RGBA8888 image for the GPU. In case you define a bitmap resource as RGB565, it will be generated as RGB565 and provided as RGB565 image for the GPU.

I hope the topic is more clear now.

Best regards,

Manfred.