How to get proper transparency on images ? I have noise on rendering

How-to
21

You think it is converted image issue due to my software ?
but

22

Hi I think I found something, but I do not understand

green image 
in lv_draw_basic.c Line 504
if ((col == 0)&& (row == 0)) {
                    printf("Transparency : %#08X, Lime color:%#08X\n", LV_COLOR_TRANSP, LV_COLOR_MAKE( 0x00, 0xFF, 0x00) );
                    printf("chroma_key: %#08X, px_color.full:%#08X, disp->driver.color_chroma_key.full:%#08X\n",chroma_key, px_color.full, disp->driver.color_chroma_key.full);
                }

#define LV_COLOR_TRANSP    LV_COLOR_MAKE( 0x00 , 0xFF, 0x00) 

Transparency : 0XFFFFF81F, full green color:0X0007E0
chroma_key: 0X000001, px_color.full:0X0007E0, disp->driver.color_chroma_key.full:0X00F81F

LV_COLOR_TRANSP and LV_COLOR_MAKE( 0x00 , 0xFF, 0x00) should be identical but they are not with green color

purple image
in lv_draw_basic.c Line 504
if ((col == 0)&& (row == 0)) {
                    printf("Transparency : %#08X, purple color:%#08X\n", LV_COLOR_TRANSP, LV_COLOR_MAKE( 0xFF, 0x00, 0XFF) );
                    printf("chroma_key: %#08X, px_color.full:%#08X, disp->driver.color_chroma_key.full:%#08X\n",chroma_key, px_color.full, disp->driver.color_chroma_key.full);
                }
in lv_conf.h
#define LV_COLOR_TRANSP    LV_COLOR_MAKE( 0xFF, 0x00, 0xFF )
Transparency : 0XFFFFF81F, purple color:0XFFFFF81F
chroma_key: 0X000001, px_color.full:0X00F81F, disp->driver.color_chroma_key.full:0X00F81F

LV_COLOR_TRANSP and LV_COLOR_MAKE( 0xFF, 0x00, 0xFF ) are identical with purple

23

Are you sure that you are using that lv_conf.h file (and that LittlevGL gets recompiled whenever lv_conf.h is changed)? The value of LV_COLOR_TRANSP did not change which means that LittlevGL was not recompiled to take the new value into account.

24

Beat me, burn me , hit me ā€¦ yes my mistake !!!
It seems I have mess up with lv_conf_checker.h when I started to test littlevgl and having issue to get correct transparency so I forced this color
LV_COLOR_TRANSP was forced to #define LV_COLOR_TRANSP LV_COLOR_MAKE( 0xFF, 0x00, 0xFF ) in it and I forgot.

Sorry for the noise, I will deleted my current lib and download a clean one in case I did others changes during initial tests

Big appologiesā€¦ and thank you for your patience

25

No problem.

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