Correctly render BW image

imagescrollareagl.cpp

@@ -64,6 +64,7 @@ void ImageWidget::setImage(RawImage *image)
         break;
     }
     m_image->generateMipMaps();
+    m_bwImg = true;
     update();
 }
 
@@ -79,6 +80,7 @@ void ImageWidget::setImage(const QPixmap &pixmap)
     m_image->setMinMagFilters(QOpenGLTexture::LinearMipMapLinear, QOpenGLTexture::Linear);
     m_image->setWrapMode(QOpenGLTexture::ClampToBorder);
     m_image->setBorderColor(0, 0, 0, 0);
+    m_bwImg = false;
     update();
 }
 
@@ -167,6 +169,7 @@ void ImageWidget::paintGL()
     m_program->setUniformValue("stretch", m_stretch);
     m_program->setUniformValue("a", m_param);
     m_program->setUniformValue("zoom", 1.0f/m_scale);
+    m_program->setUniformValue("bw", m_bwImg);
 
     m_image->bind(0);
     f->glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);