BUFFER_BIT, filter);
    wtu.glErrorShouldBe(gl, gl.NO_ERROR, "blitframebuffer should succeed");

    // Read pixels from srgb images and linear images
    var srgbPixels0 = new Uint8Array(dstSize * dstSize * 4);
    var srgbPixels1 = new Uint8Array(dstSize * dstSize * 4);
    var linearPixels0 = new Uint8Array(dstSize * dstSize * 4);
    var linearPixels1 = new Uint8Array(dstSize * dstSize * 4);
    gl.bindFramebuffer(gl.READ_FRAMEBUFFER, fbo_draw);
    if (drawbuffersFormatMask & srgbMask) {
        gl.re