Force RGB565

[JJSarrasin]

Hi,

I'm working on low-end devices TV and I would like to try coil to force using RGB565. I'm not a specialist, but from what I read, it should reduce the amount of memory used.

I try with the following ImageRequest Builder:

var requestBuilder = ImageRequest
    .Builder(context)
    .data("https://picsum.photos/400/200.jpg")
    .allowHardware(false)
    .allowRgb565(true)
    .bitmapConfig(android.graphics.Bitmap.Config.RGB_565)
    .transformations(LogBitmapConfigTransformation("LogBitmapConfig"))
    .crossfade(0)

class LogBitmapConfigTransformation(override val cacheKey: String) : Transformation() {
    override suspend fun transform(input: Bitmap, size: Size): Bitmap {
        Log.e("WTF", "Bitmap config: ${input.config}")
        return input
    }
}

But it still output "Bitmap config: ARGB_8888".
Any idea why ?

In addition, which format works best on low-end devices, jpg, png, webP ? The best trade-off between image size, CPU decompression and memory usage ?

[colinrtwhite]

Using a transformation forces ARGB_8888. This is to simplify transitions so they don't have to account for different pixel formats when modifying pixels.

[JJSarrasin]

Thanks, how can I be sure the rendering is rgb565 according coil criteria without this log ?