# Using \`draw-bitmap\` and \`draw-bitmap-section\` with transparent color images
**URL:** https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694
**Category:** Questions & Answers
**Created:** [February 14, 2022, 2:33pm UTC](https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694 "2022-02-14T14:33:29Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@soegaard](https://racket.discourse.group/u/soegaard)
#### Post date: [February 14, 2022, 2:33pm UTC](https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694/1 "2022-02-14T14:33:29Z")
Hi All,
I need help to draw a "sprite" (small bitmap) on top of a bitmap.
The sprite in question is consists of a transparent background and has a solid yellow circle in the center.
My test program looks like this (scroll to see the end of the program):
```scheme
#lang racket
(require racket/gui)
(define w 200)
(define h 200)
(define bm (make-object bitmap% w h))
(define dc (new bitmap-dc% [bitmap bm]))
(define black (send the-color-database find-color "black"))
(define sprite (make-object bitmap% "sprites.png"))
(send dc set-background black)
(send dc clear)
bm
sprite
(send dc set-smoothing 'unsmoothed)
(send dc draw-bitmap-section
sprite ; source
0 0 ; dest
0 0 16 16 ; source
'solid ; ignored for color bitmaps
black ; ignored for color bitmaps
sprite ; use the α channel as mask
)
bm
```
The output is shown below. It shows that the sprite is drawn on top of the black background.
I was expecting a "solid" yellow, but the black background is seen below the sprite.
Why?
The image "sprites.png" is here:
---
### Author:  [@simonls](https://racket.discourse.group/u/simonls)
#### Post date: [February 14, 2022, 3:01pm UTC](https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694/2 "2022-02-14T15:01:50Z")
I think I found a fix:
```scheme
(define sprite (make-object bitmap% "sprites.png" 'png/alpha))
```
I think for some reason the implementation decides to just load your particular image with kind `'png` so to force it to load it with alpha I set it explicitly. I am not sure how it decides what kind to use when it is implicitly choosen and whether it can be influenced by the image and what format it has etc.
But I could imagine that images with particular formats may have different kinds assigned implicitly.
For example I saw that your image uses indexed colors with an alpha channel which is relatively rare in circumstances I am used too, maybe that influences it? Well all of that is speculation for more answers we would have to dig into the implementation...
---
### Author:  [@soegaard](https://racket.discourse.group/u/soegaard)
#### Post date: [February 14, 2022, 3:06pm UTC](https://racket.discourse.group/t/using-draw-bitmap-and-draw-bitmap-section-with-transparent-color-images/694/3 "2022-02-14T15:06:40Z")
That's it!
I assumed that the png was loaded with its alpha channel automatically.
Thanks for find the error - it was beginning to bug me 🙂